Low-particle gas enclosure systems and methods

ABSTRACT

A method comprises processing a substrate in a gas enclosure to form a film on one or more portions of the substrate. The method further comprises, while processing the substrate, circulating gas along a circulation path through the gas enclosure. Circulating the gas may comprise flowing gas through an exhaust housing enclosing a printhead assembly housed in the gas enclosure and filtering the gas flowing downstream of the printhead assembly from the exhaust housing.

CROSS REFERENCE TO RELATED CASES

This application is a continuation of U.S. application Ser. No.16/791,408, filed Feb. 14, 2020, which is a continuation of U.S.application Ser. No. 16/102,392, filed Aug. 13, 2018, now U.S. Pat. No.10,654,299, issued May 19, 2020, which is a continuation of U.S.application Ser. No. 14/275,637, filed May 12, 2014, now U.S. Pat. No.10,434,804, issued Oct. 8, 2019, which claims priority from U.S.Provisional Application No. 61/911,934, filed Dec. 4, 2013; U.S.Provisional Application No. 61/983,417, filed Apr. 23, 2014; U.S.Provisional Application No. 61/925,578, filed Jan. 9, 2014. U.S.application Ser. No. 14/275,637 is a continuation-in-part of U.S.application Ser. No. 14/205,340, filed Mar. 11, 2014, now U.S. Pat. No.9,605,245, issued on Mar. 28, 2017, which is a continuation-in-part ofU.S. application Ser. No. 13/802,304, filed Mar. 13, 2013, now U.S. Pat.No. 9,048,344, issued on Jun. 2, 2015, which is a continuation-in-partof U.S. application Ser. No. 13/720,830, filed Dec. 19, 2012, now U.S.Pat. No. 8,899,171, issued Dec. 2, 2014, which claims priority from U.S.Provisional Application No. 61/579,233, Dec. 22, 2011. U.S. applicationSer. No. 13/720,830 is a continuation-in-part of U.S. application Ser.No. 12/652,040, filed Jan. 5, 2010, now U.S. Pat. No. 8,383,202, issuedFeb. 26, 2013, which is a continuation-in-part of U.S. application Ser.No. 12/139,391, filed Jun. 13, 2008, now abandoned, which claimspriority from U.S. Provisional Application No. 61/142,575, filed Jan. 5,2009. All cross-referenced applications listed herein are incorporatedby reference in their entirety.

FIELD

The present teachings relate to various embodiments of a gas enclosuresystem that have an inert, substantially low-particle environment forfabrication of OLED panels on a variety of substrates sizes andsubstrate materials.

OVERVIEW

Interest in the potential of organic light-emitting diode (OLED) displaytechnology has been driven by OLED display technology attributes thatinclude demonstration of display panels that have highly saturatedcolors, are high-contrast, ultrathin, fast-responding, and energyefficient. Additionally, a variety of substrate materials, includingflexible polymeric materials, can be used in the fabrication of OLEDdisplay technology. Though the demonstration of displays for smallscreen applications, primarily for cell phones, has served to emphasizethe potential of the technology, challenges remain in scaling highvolume manufacturing across a range of substrate formats in high yield.

With respect to scaling of formats, a Gen 5.5 substrate has dimensionsof about 130 cm×150 cm and can yield about eight 26″ flat paneldisplays. In comparison, larger format substrates can include using Gen7.5 and Gen 8.5 mother glass substrate sizes. A Gen 7.5 mother glass hasdimensions of about 195 cm×225 cm, and can be cut into eight 42″ or six47″ flat panel displays per substrate. The mother glass used in Gen 8.5is approximately 220 cm×250 cm, and can be cut to six 55″ or eight 46″flat panel displays per substrate. One indication of the challenges thatremain in scaling of OLED display manufacturing to larger formats isthat the high-volume manufacture of OLED displays in high yield onsubstrates larger than Gen 5.5 substrates has proven substantiallychallenging.

In principle, an OLED device may be manufactured by the printing ofvarious organic thin films, as well as other materials, on a substrateusing an OLED printing system. Such organic materials can be susceptibleto damage by oxidation and other chemical processes. Housing an OLEDprinting system in a fashion that can be scaled for various substratesizes and can be done in an inert, substantially low-particle printingenvironment can present a variety of engineering challenges.Manufacturing tools for high throughput large-format substrate printing,for example, such as printing of Gen 7.5 and Gen 8.5 substrates, requiresubstantially large facilities. Accordingly, maintaining a largefacility under an inert atmosphere, requiring gas purification to removereactive atmospheric species, such as water vapor and oxygen, as well asorganic solvent vapors, as well as maintaining a substantiallylow-particle printing environment, has proven to be significantlychallenging.

As such, challenges remain in scaling high volume manufacturing of OLEDdisplay technology across a range of substrate formats in high yield.Accordingly, there exists a need for various embodiments a gas enclosuresystem of the present teachings that can house an OLED printing system,in an inert, substantially low-particle environment, and can be readilyscaled to provide for fabrication of OLED panels on a variety ofsubstrates sizes and substrate materials. Additionally, various gasenclosure systems of the present teachings can provide for ready accessto an OLED printing system from the exterior during processing and readyaccess to the interior for maintenance with minimal downtime.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the features and advantages of the presentdisclosure will be obtained by reference to the accompanying drawings,which are intended to illustrate, not limit, the present teachings.

FIG. 1 is right, front perspective view of a gas enclosure assembly inaccordance with various embodiments of the present teachings.

FIG. 2 depicts an exploded view of a gas enclosure assembly inaccordance with various embodiments of the present teachings.

FIG. 3 is an exploded front perspective view of a frame member assemblydepicting various panel frame sections, and section panels in accordancewith various embodiments of the present teachings.

FIG. 4A trough FIG. 4C are top schematic views of various embodiments ofgasket seals for forming joints.

FIG. 5A and FIG. 5B are various perspective views that depict sealing offrame members according to various embodiments of a gas enclosureassembly of the present teachings.

FIG. 6A and FIG. 6B are various views relating to sealing of a sectionpanel for receiving a readily-removable service window according tovarious embodiments of a gas enclosure assembly of the presentteachings.

FIG. 7A and FIG. 7B are enlarged perspective section views relating tosealing of a section panel for receiving an inset panel or window panelaccording to various embodiments of the present teachings.

FIG. 8 is a view of a ceiling including a lighting system for variousembodiments of a gas enclosure system in accordance with the presentteachings.

FIG. 9 is a front perspective view of view of a gas enclosure assemblyin accordance with various embodiments of the present teachings.

FIG. 10A depicts an exploded view of various embodiments of a gasenclosure assembly as depicted in FIG. 9 and related printing inaccordance with various embodiments of the present teachings. FIG. 10Bdepicts an expanded iso perspective view of the printing system depictedin FIG. 10A. FIG. 10C shows an expanded iso perspective view of anauxiliary enclosure depicted in FIG. 10A.

FIG. 11 depicts a perspective view of a floatation table according tovarious embodiments of the present teachings.

FIG. 12 is a schematic view of various embodiments of gas enclosureassembly and related system components the present teachings.

FIG. 13 is a schematic view of various embodiments of gas enclosureassembly and related system components the present teachings.

FIG. 14 is a schematic of a gas enclosure system in accordance withvarious embodiments of the present teachings.

FIG. 15 is a schematic of a gas enclosure system in accordance withvarious embodiments of the present teachings.

FIG. 16 is a phantom front perspective view of a gas enclosure assembly,which depicts ductwork installed in the interior of a gas enclosureassembly in accordance with various embodiments of the presentteachings.

FIG. 17 is a phantom top perspective view of a gas enclosure assembly,which depicts ductwork installed in the interior of a gas enclosureassembly in accordance with various embodiments of the presentteachings.

FIG. 18 is a phantom bottom perspective view of a gas enclosureassembly, which depicts ductwork installed in the interior of a gasenclosure assembly in accordance with various embodiments of the presentteachings.

FIG. 19A is a schematic representation showing a service bundleaccording to various embodiments of the present teachings. FIG. 19Bdepicts gas sweeping past a service bundle that is fed through variousembodiments of ductwork according to the present teachings.

FIG. 20 is a schematic representation showing how reactive species (A)occluded in dead-spaces of a service bundle are actively purged frominert gas (B) sweeping through a duct through which the bundles havebeen routed.

FIG. 21A is a phantom perspective view of cables and tubing routedthrough ductwork according to various embodiments of a gas enclosuresystem of the present teachings. FIG. 21B is an enlarged view of anopening shown in FIG. 21A, showing detail of a cover for closure overthe opening, according to various embodiments of a gas enclosure systemof the present teachings.

FIG. 22 is a schematic side section view of a gas enclosure systemdepicting an embodiment of gas circulation through a gas enclosureassembly according to various embodiments of the present teachings.

FIG. 23 is a schematic side section view of a gas enclosure systemdepicting an embodiment of gas circulation through a gas enclosureassembly according to various embodiments of the present teachings.

FIG. 24 is a schematic front section view of a gas enclosure depictingan embodiment of gas circulation through a gas enclosure assemblyaccording to various embodiments of the present teachings.

FIG. 25 is a cross-sectional schematic view of a gas enclosure assemblywith system components in accordance with various embodiments of thepresent teachings.

FIG. 26 is a perspective view of a printing system depicting variousembodiments of a particle control system of the present teaching, whichcan include a low-particle X-axis motion system and service bundlehousing exhaust system.

FIG. 27A and FIG. 27B are section views of a low-particle X-axis motionsystem according to various embodiments of the present teachings.

FIG. 28A and FIG. 28B are various perspective views of a service bundlehousing exhaust system for a printing system according to variousembodiments of the present teachings.

FIG. 29A is schematic view of a service bundle housing exhaust systemaccording to various embodiments of the present teachings. FIG. 29B,FIG. 29C, and FIG. 29D are schematic views of various embodiments ofventing a service bundle housing according to various embodiments of thepresent teachings.

FIG. 30A and FIG. 30B are schematic diagrams of a gas enclosure systemdepicting an embodiment of gas circulation and particle collectionaround a printhead assembly in a gas enclosure assembly according tovarious embodiments of the present teachings.

FIG. 31A and FIG. 31B are schematic diagrams of a gas enclosure systemdepicting an embodiment of gas circulation and particle collectionaround a printhead assembly in a gas enclosure assembly according tovarious embodiments of the present teachings.

FIG. 32A and FIG. 32B are schematic diagrams of a gas enclosure systemdepicting an embodiment of gas circulation and particle collectionaround a printhead assembly in a gas enclosure assembly according tovarious embodiments of the present teachings.

FIG. 33 is an embodiment of a portable airborne particle counting deviceaccording to the present teachings.

FIG. 34 is a schematic representation of the principle of operation ofvarious portable airborne particle counting devices based on scatteringof electromagnetic radiation.

FIG. 35 is a schematic representation depicting various areas where aportable airborne particle counting device can be located in variousprinting systems of the present teachings.

FIG. 36 is an iso perspective view of a portable airborne particlecounting device located proximal to a substrate support apparatus inaccordance with various embodiments of the present teachings.

FIG. 37A and FIG. 37B are graphs depicting long-term test results ofparticle counts in various embodiments of a gas enclosure system of thepresent teaching.

FIG. 38 is a graph depicting recovery test results of particle countsbefore and after a gas enclosure system window opening.

FIG. 39 is a schematic representation of the principle of operation ofvarious particle detection devices for on-substrate particle detectionbased on scattering of electromagnetic radiation.

FIG. 40 is an iso perspective view of the placement of test substrateproximal to a printing area in accordance with various embodiments ofthe present teachings.

FIG. 41 is an iso perspective view of the placement of substrateproximal to a printing area in a printing system equipped with a camerain accordance with various embodiments of the present teachings.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present teachings disclose various embodiments of a gas enclosureassembly that can house an OLED printing system. Various embodiments ofa gas enclosure assembly can be sealably constructed and integrated withvarious components that provide a particle control system, a gascirculation and filtration system, a gas purification system, and thelike to form various embodiments of a gas enclosure system that cansustain an inert gas environment that is substantially low-particle forprocesses requiring such an environment.

Manufacturing tools that in principle can allow for the printing of avariety of substrate sizes that includes large-format substrate sizes,can require substantially large facilities for housing such OLEDmanufacturing tools. Accordingly, maintaining an entire large facilityunder an inert atmosphere presents engineering challenges, such ascontinual purification of a large volume of an inert gas. According tothe present teachings, an inert gas may be any gas that does not undergoa chemical reaction under a defined set of conditions. Some commonlyused non-limiting examples of an inert gas can include nitrogen, any ofthe noble gases, and any combination thereof. Additionally, providing alarge facility that is essentially hermetically sealed to preventcontamination of various reactive atmospheric gases, such as water vaporand oxygen, as well as organic solvent vapors generated from variousprinting process poses an engineering challenge. According to thepresent teachings, an OLED printing facility would maintain levels foreach species of various reactive species, including various reactiveatmospheric gases, such as water vapor and oxygen, as well as organicsolvent vapors at 100 ppm or lower, for example, at 10 ppm or lower, at1.0 ppm or lower, or at 0.1 ppm or lower.

Continual maintenance of a large facility requiring an inert environmentposes still additional challenges. For example, of a manufacturingfacility can require a substantial length of various service bundlesthat can be operatively connected from various systems and assemblies toprovide optical, electrical, mechanical, and fluidic connectionsrequired to operate, for example, but not limited by, a printing system.According to the present teachings, a service bundle can include, by wayof non-limiting example, optical cables, electrical cables, wires andtubing, and the like. Various embodiments of a service bundle accordingto the present teachings can have a significant total dead volume as aresult of a substantial number of void spaces created by bundlingvarious cables, wires and tubing, and the like together in a servicebundle. The total dead volume resulting from a substantial number ofvoid spaces in a service bundle can result in the retention of asignificant volume of reactive gaseous species occluded therein. Such asignificant volume of occluded reactive gaseous species can presentchallenges for effectively bringing a gas enclosure into specificationwith respect to levels of reactive atmospheric constituents, such asoxygen and water vapor, as well as organic vapors. Moreover, suchservice bundles used in the operation of a printing system can be anongoing source of particulate matter.

In that regard, providing and maintaining a substantially inert andlow-particle environment in an OLED manufacturing facility providesadditional challenges not presented for processes that can be done, forexample, in atmospheric conditions under open air, high flow laminarflow filtration hoods. As such, various embodiments of systems andmethods of the present teachings address the challenges presented forOLED printing of OED substrates of a variety of sizes and materials inan inert, substantially low-particle environment.

Regarding maintaining a substantially low-particle environment, variousembodiments of a gas circulation and filtration system can be designedto provide a low particle inert gas environment for airborneparticulates meeting the standards of International StandardsOrganization Standard (ISO) 14644-1:1999, “Cleanrooms and associatedcontrolled environments—Part 1: Classification of air cleanliness,” asspecified by Class 1 through Class 5. However, controlling airborneparticulate matter alone is not sufficient for providing a low-particleenvironment proximal to a substrate during, for example, but not limitedby, a printing process, as particles generated proximal to a substrateduring such a process can accumulate on a substrate surface before theycan be swept through a gas circulation and filtration system.

Accordingly, various embodiments of a gas enclosure system of thepresent teachings can have a particle control system that can includecomponents in addition to a gas circulation and filtration system thatcan provide a low-particle zone proximal to a substrate duringprocessing in a printing step. According to various embodiments of a gasenclosure system of the present teachings, a particle control system forvarious embodiments of a gas enclosure system of the present teachingscan include a gas circulation and filtration system, alow-particle-generating X-axis linear bearing system for moving aprinthead assembly relative to a substrate, a service bundle housingexhaust system, and a printhead assembly exhaust system. In that regard,in addition to a circulation and filtration system for maintaining asubstantially low-particle specification for airborne particulatematter, various embodiments of a gas enclosure system of the presentteaching can have a particle control system that can include additionalcomponents for maintaining a substantially low-particle specificationfor particulate matter deposited on a substrate.

Various embodiments of systems and methods of the present teachings canmaintain a substantially low-particle environment providing for anaverage on-substrate distribution of particles of a particular sizerange of interest that does not exceed an on-substrate deposition ratespecification. An on-substrate deposition rate specification can be setfor each of a particle size range of interest of between about 0.1 □mand greater to about 10 □m and greater. In various embodiments systemsand methods of the present teachings, an on-substrate particledeposition rate specification can be expressed as a limit of the numberof particles deposited per square meter of substrate per minute for eachof a target particle size range.

Various embodiments of an on-substrate particle deposition ratespecification can be readily converted from a limit of the number ofparticles deposited per square meter of substrate per minute to a limitof the number of particles deposited per substrate per minute for eachof a target particle size range. Such a conversion can be readily donethrough a known relationship between substrates, for example, of aspecific generation-sized substrate and the corresponding area for thatsubstrate generation. For example, Table 1 below summarizes aspectratios and areas for some known generation-sized substrates. It shouldbe understood that a slight variation of aspect ratio and hence size maybe seen from manufacturer to manufacturer. However, regardless of suchvariation, a conversion factor for a specific generation-sized substrateand an area in square meters can be obtained any of a variety ofgeneration-sized substrates.

TABLE 1 Correlation between area and substrate size Generation ID X (mm)Y (mm) Area (m2) Gen 3.0 550 650 0.36 Gen 3.5 610 720 0.44 Gen 3.5 620750 0.47 Gen 4 680 880 0.60 Gen 4 730 920 0.67 Gen 5 1100 1250 1.38 Gen5 1100 1300 1.43 Gen 5.5 1300 1500 1.95 Gen 6 1500 1850 2.78 Gen 7.51950 2250 4.39 Gen 8 2160 2400 5.18 Gen 8 2160 2460 5.31 Gen 8.5 22002500 5.50 Gen 9 2400 2800 6.72 Gen 10 2850 3050 8.69

Additionally, an on-substrate particle deposition rate specificationexpressed as a limit of the number of particles deposited per squaremeter of substrate per minute can be readily converted to any of avariety of unit time expressions. It will be readily understood that anon-substrate particle deposition rate specification normalized tominutes can be readily converted to any other expression of time throughknow relationships of time, for example, but not limited by, such assecond, hour, day, etc. Additionally, units of time specificallyrelating to processing can be used. For example, a print cycle can beassociated with a unit of time. For various embodiments of a gasenclosure system according to the present teachings a print cycle can bea period of time in which a substrate is moved into a gas enclosuresystem for printing and then removed from a gas enclosure system afterprinting is complete. For various embodiments of a gas enclosure systemaccording to the present teachings a print cycle can be a period of timefrom the initiation of the alignment of a substrate with respect to aprinthead assembly to the delivery of a last ejected drop of ink ontothe substrate. In the art of processing, total average cycle time orTACT can be an expression of a unit of time for a particular processcycle. According to various embodiments of systems and methods of thepresent teachings, TACT for a print cycle can be about 30 seconds. Forvarious embodiments of systems and methods of the present teachings,TACT for a print cycle can be about 60 seconds. In various embodimentsof systems and methods of the present teachings, TACT for a print cyclecan be about 90 seconds. For various embodiments of systems and methodsof the present teachings, TACT for a print cycle can be about 120seconds. In various embodiments of systems and methods of the presentteachings, TACT for a print cycle can be about 300 seconds.

With respect to airborne particulate matter and particle depositionwithin a system, a substantial number of variables can impact developinga general model that may adequately compute, for example, anapproximation of a value for particle fallout rate on a surface, such asa substrate, for any particular manufacturing system. Variables such asthe size of particles, the distribution of particles of particular size;surface area of a substrate and the time of exposure of a substratewithin a system can vary depending on various manufacturing systems. Forexample, the size of particles and the distribution of particles ofparticular size can be substantially impacted by the source and locationof particle-generating components in various manufacturing systems.Calculations based on various embodiments of gas enclosure systems ofthe present teachings suggest that without various particle controlsystems of the present teachings, on-substrate deposition of particulatematter per print cycle per square meter of substrate can be between morethan about 1 million to more than about 10 million particles forparticles in a size range of 0.1 □m and greater. Such calculationssuggest that that without various particle control systems of thepresent teachings, on-substrate deposition of particulate matter perprint cycle per square meter of substrate can be between more than about1000 to about more than about 10,000 particles for particles in a sizerange of about 2 □m and greater.

Various embodiments of a low-particle gas enclosure system of thepresent teachings can maintain a low-particle environment providing foran average on-substrate particle distribution that meets an on-substratedeposition rate specification of less than or equal to about 100particles per square meter of substrate per minute for particles greaterthan or equal to 10 □m in size. Various embodiments of a low-particlegas enclosure system of the present teachings can maintain alow-particle environment providing for an average on-substrate particledistribution that meets an on-substrate deposition rate specification ofless than or equal to about 100 particles per square meter of substrateper minute for particles greater than or equal to 5 □m in size. Invarious embodiments of a gas enclosure system of the present teachings,a low-particle environment can be maintained providing for an averageon-substrate particle distribution that meets an on-substrate depositionrate specification of less than or equal to about 100 particles persquare meter of substrate per minute for particles greater than or equalto 2 □m in size. In various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 1 □m in size. Various embodiments ofa low-particle gas enclosure system of the present teachings canmaintain a low-particle environment providing for an averageon-substrate particle distribution that meets an on-substrate depositionrate specification of less than or equal to about 1000 particles persquare meter of substrate per minute for particles greater than or equalto 0.5 □m in size. For various embodiments of a gas enclosure system ofthe present teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.3 □m in size. Various embodimentsof a low-particle gas enclosure system of the present teachings canmaintain a low-particle environment providing for an averageon-substrate particle distribution that meets an on-substrate depositionrate specification of less than or equal to about 1000 particles persquare meter of substrate per minute for particles greater than or equalto 0.1

m in size.

As previously discussed herein, high volume manufacture of OLED displaysin high yield on substrates larger than Gen 5.5 substrates, has provento be substantially challenging. For clearer perspective regardingsubstrate sizes that can be used in manufacturing of various OLEDdevise, generations of mother glass substrate sizes have been undergoingevolution for flat panel displays fabricated by other-than OLED printingsince about the early 1990's. The first generation of mother glasssubstrates, designated as Gen 1, is approximately 30 cm×40 cm, andtherefore could produce a 15″ panel. Around the mid-1990's, the existingtechnology for producing flat panel displays had evolved to a motherglass substrate size of Gen 3.5, which has dimensions of about 60 cm×72cm. In comparison, a Gen 5.5 substrate has dimensions of about 130cm×150 cm.

As generations have advanced, mother glass sizes for Gen 7.5 and Gen 8.5are in production for other-than OLED printing fabrication processes. AGen 7.5 mother glass has dimensions of about 195 cm×225 cm, and can becut into eight 42″ or six 47″ flat panels per substrate. The motherglass used in Gen 8.5 is approximately 220×250 cm, and can be cut to six55″ or eight 46″ flat panels per substrate. The promise of OLED flatpanel display for qualities such as truer color, higher contrast,thinness, flexibility, transparency, and energy efficiency have beenrealized, at the same time that OLED manufacturing is practicallylimited to G 3.5 and smaller. Currently, OLED printing is believed to bethe optimal manufacturing technology to break this limitation and enableOLED panel manufacturing for not only mother glass sizes of Gen 3.5 andsmaller, but at the largest mother glass sizes, such as Gen 5.5, Gen7.5, and Gen 8.5. One of the features of OLED panel display technologyincludes that a variety of substrate materials can be used, for example,but not limited by, a variety of glass substrate materials, as well as avariety of polymeric substrate materials. In that regard, sizes recitedfrom the terminology arising from the use of glass-based substrates canbe applied to substrates of any material suitable for use in OLEDprinting.

It is contemplated that a wide variety of ink formulations can beprinted within the inert, substantially low-particle environment ofvarious embodiments of a gas enclosure system of the present teachings.During the manufacture of an OLED display, an OLED pixel can be formedto include an OLED film stack, which can emit light of a specific peakwavelength when a voltage is applied. An OLED film stack structurebetween an anode and a cathode can include a hole injection layer (HIL),a hole transport layer (HTL), an emissive layer (EL), an electrontransport layer (ETL) and an electron injection layer (EIL). In someembodiments of an OLED film stack structure, an electron transport layer(ETL) can be combined with an electron injection layer (EIL) to form anETL/EIL layer. According to the present teachings, various inkformulations for an EL for various color pixel EL films of an OLED filmstack can be printed using inkjet printing. Additionally, for example,but not limited by, the HIL, HTL, EML, and ETL/EIL layers can have inkformulations that can be printed using inkjet printing.

It is further contemplated that an organic encapsulation layer can beprinted on an OLED panel using inkjet printing. It is contemplated thatan organic encapsulation layer can be printed using inkjet printing, asinkjet printing can provide several advantages. First, a range of vacuumprocessing operations can be eliminated because such inkjet-basedfabrication can be performed at atmospheric pressure. Additionally,during an inkjet printing process, an organic encapsulation layer can belocalized to cover portions of an OLED substrate over and proximal to anactive region, to effectively encapsulate an active region, includinglateral edges of the active region. The targeted patterning using inkjetprinting results in eliminating material waste, as well as eliminatingadditional processing typically required to achieve patterning of anorganic layer. An encapsulation ink can comprise a polymer including,for example, but not limited by, an acrylate, methacrylate, urethane, orother material, as well as copolymers and mixtures thereof, which can becured using thermal processing (e.g. bake), UV exposure, andcombinations thereof.

With respect to OLED printing, according to the present teachings,maintaining substantially low levels of reactive species, for example,but not limited by, atmospheric constituents such as oxygen and watervapor, as well as various organic solvent vapors used in OLED inks, hasbeen found to correlate to providing OLED flat panel displays meetingthe requisite lifetime specifications. The lifetime specification is ofparticular significance for OLED panel technology, as this correlatesdirectly to display product longevity; a product specification for allpanel technologies, which has been challenging for OLED panel technologyto meet. In order to provide panels meeting requisite lifetimespecifications, levels of each of a reactive species, such as watervapor, oxygen, as well as organic solvent vapors, can be maintained at100 ppm or lower, for example, at 10 ppm or lower, at 1.0 ppm or lower,or at 0.1 ppm or lower with various embodiments of a gas enclosuresystem of the present teachings.

The need for printing an OLED panel in a facility in which the levels ofeach of a reactive species, such as water vapor, oxygen, as well asorganic solvent vapors, can be maintained at 100 ppm or lower, forexample, at 10 ppm or lower, at 1.0 ppm or lower, or at 0.1 ppm orlower, can be illustrated in reviewing the information summarized inTable 2. The data summarized on Table 2 resulted from the testing ofeach of a test coupon comprising organic thin film compositions for eachof red, green, and blue, fabricated in a large-pixel, spin-coated deviceformat. Such test coupons are substantially easier to fabricate and testfor the purpose of rapid evaluation of various formulations andprocesses. Though test coupon testing should not be confused withlifetime testing of a printed panel, it can be indicative of the impactof various formulations and processes on lifetime. The results shown inthe table below represent variation in the process step in thefabrication of test coupons in which only the spin-coating environmentvaried for test coupons fabricated in a nitrogen environment wherereactive species were less than 1 ppm compared to test coupons similarlyfabricated but in air instead of a nitrogen environment.

It is evident through the inspection of the data in Table 2 for testcoupons fabricated under different processing environments, particularlyin the case of red and blue, that printing in an environment thateffectively reduces exposure of organic thin film compositions toreactive species may have a substantial impact on the stability ofvarious ELs, and hence on lifetime.

TABLE 2 Impact of inert gas processing on lifetime for OLED panelsProcess V Cd/A CIE (x, y) T95 T80 T50 Color Environment @ 10 mA/cm² @1000 Cd/m² Red Nitrogen 6 9 (0.61, 0.38) 200 1750 10400 Air 6 8 (0.60,0.39) 30 700 5600 Green Nitrogen 7 66 (0.32, 0.63) 250 3700 32000 Air 761 (0.32, 0.62) 250 2450 19700 Blue Nitrogen 4 5 (0.14, 0.10) 150 7503200 Air 4 5 (0.14, 0.10) 15 250 1800

Additionally, maintaining a substantially low-particle environment forOLED printing is of particular importance, as even very small particlescan lead to a visible defect on an OLED panel. In that regard, systemsand methods of the present teachings provide for maintaining low levelsof each of a reactive species, such as water vapor, oxygen, as well asorganic solvent vapors, and additionally for maintaining a sufficientlylow-particle environment for high-quality OLED panel manufacture.Various embodiments of a gas enclosure system can have a particlecontrol system that can include components in addition to a gascirculation and filtration system to provide a low-particle zoneproximal to a substrate during processing in a printing step.

Various embodiments of gas enclosure systems of the present teachingscan have a particle control system providing a low-particle zoneproximal to a substrate for which various particle-generating componentsproximal to a substrate can be contained and exhausted to preventparticles from accumulating on a substrate during a printing process. Invarious embodiments of a gas enclosure system, a particle control systemcan include a gas circulation and filtration system for maintainingairborne particulate levels meeting the standards of InternationalStandards Organization Standard (ISO) 14644-1:1999, as specified byClass 1 through Class 5; both within a gas enclosure system, as well asproximal a substrate. Various embodiments of a particle control systemcan include a gas circulation and filtration system in fluidcommunication with particle-generating components that have beencontained, so that such particle-containing components can be exhaustedinto the gas circulation and filtration system. For various embodimentsof a particle control system, particle-generating components that havebeen contained can be exhausted into dead spaces, rendering suchparticulate matter inaccessible for recirculation within a gas enclosuresystem. Various embodiments of gas enclosure systems of the presentteachings can have a particle control system for which variouscomponents can be intrinsically low-particle generating, therebypreventing particles from accumulating on a substrate during a printingprocess. Various components of a particle control system of the presentteachings can utilize containment and exhausting of particle-generatingcomponents, as well as selection of components that are intrinsicallylow-particle generating to provide a low-particle zone proximal to asubstrate.

For various embodiments of a low-particle gas enclosure system of thepresent teachings, maintaining a substantially low-particle environmentin an enclosed system, for example, an enclosed OLED printing systemprovides additional challenges not presented by particle reduction forprocesses that can be done in atmospheric conditions, such as under openair, high flow laminar flow filtration hoods. Various embodiments of agas enclosure system can provide substantially low-particle environmentsfor example, but not limited by: 1) through elimination of areasproximal to a substrate where particulate matter can collect, 2) bycontaining and exhausting particle-generating components, such as aservice bundle that can include bundled cables, wires and tubing, andthe like, as well as various apparatuses, assemblies and systems which,for example, utilize components such as fans or linear motion systemsthat use friction bearings, within various embodiments of a particlecontrol system of the present teachings, and 3) by using a variety ofintrinsically low-particle generating pneumatically operated components,such as, but not limited by, substrate floatation tables, air bearings,and pneumatically operated robots, and the like. According to variousembodiments of a gas enclosure system of the present teachings, asubstantially low-particle environment can include a particle controlsystem including components for providing a low-particle zone proximalto a substrate during printing.

As will be discussed in more detail subsequently herein, direct controlof particle generation proximal to a substrate to provide a low-particlezone proximal to a substrate can be implemented by containment ofparticle-generating elements, by the use of low-particle generatingcomponents, and by a combination of containment of particle generationand use of low-particle generating components. Accordingly, variousembodiments of a gas enclosure system can have a particle control systemthat can include a gas circulation and filtration system in fluidcommunication with a low-particle generating X-axis linear bearingsystem for moving a printhead assembly relative to a substrate, aservice bundle housing exhaust system, and a printhead assembly exhaustsystem. For various embodiments of a service bundle housing exhaustsystem and a printhead assembly exhaust system, particles contained insuch systems can be exhausted into a gas circulation and filtrationsystem. In various embodiments of a service bundle housing exhaustsystem and a printhead assembly exhaust system, particles contained insuch systems can be exhausted into a dead space, thereby rendering suchparticulate matter so exhausted into a dead space inaccessible forcirculation within a gas enclosure system.

Additionally, system validation as well as ongoing system monitoring canbe performed for both airborne and on-substrate particle monitoring. Adetermination of airborne particulate matter can be performed forvarious embodiments of a gas enclosure system before a printing processas a quality check, using, for example, a portable particle countingdevice. In various embodiments of a gas enclosure system, adetermination of airborne particulate matter can be performed as anongoing quality check in situ while a substrate is printed. For variousembodiments of a gas enclosure system, a determination of airborneparticulate matter can be performed as a quality check before asubstrate is printed and additionally in situ while a substrate isprinted. A determination of an on-substrate distribution of particulatematter on a substrate can be performed for various embodiments of a gasenclosure system before a substrate is printed for system validation,using, for example, a test substrate. In various embodiments of a gasenclosure system, a determination of an on-substrate distribution ofparticulate matter can be performed as an ongoing quality check in situwhile a substrate is printed, for example, using a camera assemblymounted on an X-axis carriage assembly. For various embodiments of a gasenclosure system, a determination of an on-substrate distribution ofparticulate matter can be performed for system validation before asubstrate is printed and additionally in situ while a substrate isprinted.

Various embodiments of a gas enclosure system can have a particlecontrol system that can maintain a substantially low-particleenvironment providing for an on-substrate particle specification forparticles of between about 0.1

m or greater to about 10

m or greater. Various embodiments of an on-substrate particlespecification can be readily converted from an average on-substrateparticle distribution per square meter of substrate per minute to anaverage on-substrate particle distribution per substrate per minute foreach of a target particle size range. As previously discussed herein,such a conversion can be readily done through a known relationshipbetween substrates, for example, of a specific generation-sizedsubstrate and the corresponding area for that substrate generation.Additionally, an average on-substrate particle distribution per squaremeter of substrate per minute can be readily converted to any of avariety of unit time expressions. For example, in addition toconversions between standard units of time; e.g. seconds, minutes, anddays, units of time specifically relating to processing can be used. Forexample, as previously discussed herein, a print cycle can be associatedwith a unit of time.

Various embodiments of a low-particle gas enclosure system of thepresent teachings can maintain a low-particle environment providing foran average on-substrate particle distribution that meets an on-substratedeposition rate specification of less than or equal to about 100particles per square meter of substrate per minute for particles greaterthan or equal to 10

m in size. Various embodiments of a low-particle gas enclosure system ofthe present teachings can maintain a low-particle environment providingfor an average on-substrate particle distribution that meets anon-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 5

m in size. In various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 2

m in size. In various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 1

m in size. Various embodiments of a low-particle gas enclosure system ofthe present teachings can maintain a low-particle environment providingfor an average on-substrate particle distribution that meets anon-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.5

m in size. For various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.3

m in size. Various embodiments of a low-particle gas enclosure system ofthe present teachings can maintain a low-particle environment providingfor an average on-substrate particle distribution that meets anon-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.1

m in size.

Additionally, it is contemplated that a gas enclosure system would haveattributes that include, for example, but are not limited by, a gasenclosure assembly that can be readily scaled to provide an optimizedworking space for an OLED printing system, while providing minimizedinert gas volume, and additionally providing ready access to an OLEDprinting system from the exterior during processing, while providingaccess to the interior for maintenance with minimal downtime. In thatregard, various embodiments of a gas enclosure assembly having utilityfor various air-sensitive processes that require an inert environmentcan include a plurality of wall frame and ceiling frame members that canbe sealed together. In some embodiments, a plurality of wall frame andceiling frame members can be fastened together using reusable fasteners,for example, bolts and threaded holes. For various embodiments of a gasenclosure assembly according to the present teachings, a plurality offrame members, each frame member comprising a plurality of panel framesections, can be constructed to define a gas enclosure frame assembly.Various embodiments of a gas enclosure assembly can include an auxiliaryenclosure constructed as a section of a gas enclosure assembly that canbe sealably isolated from a working volume of a gas enclosure system,such as a printing system enclosure. Such physical isolation of anauxiliary enclosure from, for example, a printing system enclosure, canenable various procedures, for example, but not limited by, variousmaintenance procedures on a printhead assembly, to be conducted withlittle or no interruption of a printing process, thereby minimizing oreliminating gas enclosure system downtime.

A gas enclosure assembly of the present teachings can be designed toaccommodate a printing system, such as an OLED printing system, in afashion that can minimize the volume of the enclosure around a system.Various embodiments of a gas enclosure assembly can be constructed in afashion that minimizes the internal volume of a gas enclosure assembly,and at the same time optimizes the working space to accommodate variousfootprints of various OLED printing systems. An OLED printing systemaccording to various embodiments of a gas enclosure system of thepresent teachings, can comprise, for example, a granite base, a moveablebridge that can support an OLED printing device, one or more devices andapparatuses running from various embodiments of a pressurized inert gasrecirculation system, such as a substrate floatation table, airbearings, tracks, rails, an ink-jet printer system for depositing OLEDfilm-forming material onto substrates, including an OLED ink supplysubsystem and an inkjet printhead, one or more robots, and the like.Given the variety of components that can comprise OLED printing system,various embodiments of OLED printing system can have a variety offootprints and form factors. Various embodiments of a gas enclosureassembly so constructed additionally provide ready access to theinterior of a gas enclosure assembly from the exterior during processingand readily access to the interior for maintenance, while minimizingdowntime. In that regard, various embodiments of a gas enclosureassembly according to the present teachings can be contoured withrespect to various footprints of various OLED printing systems.According to various embodiments, once the contoured fame members areconstructed to form a gas enclosure frame assembly, various types ofpanels may be sealably installed in a plurality of panel sectionscomprising a frame member to complete the installation of a gasenclosure assembly. In various embodiments of a gas enclosure assembly,a plurality of frame members including, for example, but not limited by,a plurality of wall frame members and at least one ceiling frame member,as well as a plurality of panels for installation in panel framesections, may be fabricated at one location or locations, and thenconstructed at another location. Moreover, given the transportablenature of components used to construct a gas enclosure assembly of thepresent teachings, various embodiments of a gas enclosure assembly canbe repeatedly installed and removed through cycles of construction anddeconstruction.

In order to ensure that a gas enclosure is hermetically sealed, variousembodiments of a gas enclosure assembly of the present teaching providefor joining each frame member to provide frame sealing. The interior canbe sufficiently sealed, for example, hermetically sealed, bytight-fitting intersections between the various frame members, whichinclude gaskets or other seals. Once fully constructed, a sealed gasenclosure assembly can comprise an interior and a plurality of interiorcorner edges, at least one interior corner edge provided at theintersection of each frame member with an adjacent frame member. One ormore of the frame members, for example, at least half of the framemembers, can comprise one or more compressible gaskets fixed along oneor more respective edges thereof. The one or more compressible gasketscan be configured to create an hermetically sealed gas enclosureassembly once a plurality of frame members are joined together, andgas-tight panels installed. A sealed gas enclosure assembly can beformed having corner edges of frame members sealed by a plurality ofcompressible gaskets. For each frame member, for example, but notlimited by, an interior wall frame surface, a top wall frame surface, avertical side wall frame surface, a bottom wall frame surface, and acombination thereof can be provided with one or more compressiblegaskets.

For various embodiments of a gas enclosure assembly, each frame membercan comprise a plurality of sections framed and fabricated to receiveany of a variety of panel types that can be sealably installed in eachsection to provide a gas-tight panel seal for each panel. In variousembodiments of a gas enclosure assembly of the present teachings, eachsection frame can have a section frame gasket that, with selectedfasteners, ensures each panel installed in each section frame canprovide a gas-tight seal for each panel, and therefore for afully-constructed gas enclosure. In various embodiments, a gas enclosureassembly can have one or more of a window panel or service window ineach of a wall panel; where each window panel or service window can haveat least one gloveport. During assembly of a gas enclosure assembly,each gloveport can have a glove attached, so that the glove can extendinto the interior. According to various embodiments, each gloveport canhave hardware for mounting a glove, wherein such hardware utilizesgasket seals around each gloveport that provide a gas-tight seal tominimize leakage or molecular diffusion through the gloveport. Forvarious embodiments of a gas enclosure assembly of the presentteachings, the hardware is further designed for providing ease ofcapping and uncapping a gloveport to an end-user.

Various embodiments of a gas enclosure system according to the presentteachings can include a gas enclosure assembly formed from a pluralityof frame members and panel sections, as well as gas circulation,filtration and purification components. For various embodiments of a gasenclosure system, ductwork may be installed during the assembly process.According to various embodiments of the present teachings, ductwork canbe installed within a gas enclosure frame assembly, which has beenconstructed from a plurality of frame members. In various embodiments,ductwork can be installed on a plurality of frame members before theyare joined to form a gas enclosure frame assembly. Ductwork for variousembodiments of a gas enclosure system can be configured such thatsubstantially all gas drawn into the ductwork from one or more ductworkinlets is moved through various embodiments of a gas filtration loop forremoving particulate matter internal to a gas enclosure system.Additionally, ductwork of various embodiments of a gas enclosure systemcan be configured to separate the inlets and outlets of a gaspurification loop that is external to a gas enclosure assembly from agas filtration loop that is internal to a gas enclosure assembly.According to various embodiments of a gas enclosure system of thepresent teachings, a gas circulation and filtration system can be influid communication with, for example, but not limited by, components ofa particle control system. For various embodiments of a gas enclosureassembly, a gas circulation and filtration system can be in fluidcommunication with a service bundle housing exhaust system. For variousembodiments of a gas enclosure assembly, a gas circulation andfiltration system can be in fluid communication with a printheadassembly exhaust system. In various embodiments of a gas enclosuresystem, various components of a particle control system in fluidcommunication with a gas circulation and filtration system can provide alow-particle zone proximal to a substrate positioned in a printingsystem.

For example, a gas enclosure system can have a gas circulation andfiltration system internal a gas enclosure assembly. Such an internalfiltration system can have a plurality of fan filter units within theinterior, and can be configured to provide a laminar flow of gas withinthe interior. The laminar flow can be in a direction from a top of theinterior to a bottom of the interior, or in any other direction.Although a flow of gas generated by a circulating system need not belaminar, a laminar flow of gas can be used to ensure thorough andcomplete turnover of gas in the interior. A laminar flow of gas can alsobe used to minimize turbulence, such turbulence being undesirable as itcan cause particles in the environment to collect in such areas ofturbulence, preventing the filtration system from removing thoseparticles from the environment. Further, to maintain a desiredtemperature in the interior, a thermal regulation system utilizing aplurality of heat exchangers can be provided, for example, operatingwith, adjacent to, or used in conjunction with, a fan or another gascirculating device. A gas purification loop can be configured tocirculate gas from within the interior of a gas enclosure assemblythrough at least one gas purification component exterior the enclosure.In that regard, a circulation and filtration system internal to a gasenclosure assembly in conjunction with a gas purification loop externalto a gas enclosure assembly can provide continuous circulation of asubstantially low-particulate inert gas having substantially low levelsof reactive species throughout a gas enclosure system. Variousembodiments of a gas enclosure system having a gas purification systemcan be configured to maintain very low levels of undesired components,for example, organic solvents and vapors thereof, as well as water,water vapor, oxygen, and the like.

In addition to providing for the gas circulation, filtration andpurification components, the ductwork can be sized and shaped toaccommodate therein at least one service bundle. According to thepresent teachings, a service bundle can include, for example, but notlimited by, optical cables, electrical cables, wires, as well as variousfluid-containing tubings, and the like. Various embodiments of a servicebundle of the present teachings can have a considerable dead volumecreated by void spaces that form between various components of a servicebundle. The substantial dead volume which can be created in the bundlingof various optical cables, electrical cables, wires, andfluid-containing tubings can have a substantial volume of reactiveatmospheric species, such as water, water vapor, oxygen, and the like,trapped in void spaces. Such a substantial volume of occluded reactiveatmospheric species can be difficult to remove rapidly by a purificationsystem. Additionally, such service bundles are an identified source ofparticulate matter. In some embodiments, a combination of any of cables,electrical wires and wire bundles, and fluid-containing tubing can bedisposed substantially within the ductwork and can be operativelyassociated with at least one of an optical system, an electrical system,a mechanical system, and a cooling system, respectively, which arehoused within the interior of a gas enclosure system. As the gascirculation, filtration and purification components can be configuredsuch that essentially all circulated inert gas is drawn through theductwork, both particulate matter arising from such bundles, as well asatmospheric constituents trapped in the dead volume of variously bundledmaterials can be effectively removed by having such bundled componentssubstantially contained within the ductwork.

Various embodiments of a gas enclosure system according to the presentteachings can include a gas enclosure assembly formed from a pluralityof frame members and panel sections, as well as a particle controlsystem, gas circulation, filtration and purification components, andadditionally various embodiments of a pressurized inert gasrecirculation system. Such a pressurized inert gas recirculation systemcan be utilized in the operation of an OLED printing system for variouspneumatically-driven devices and apparatuses, as will be discussed inmore detail subsequently herein.

According to the present teachings, several engineering challenges wereaddressed in order to provide for various embodiments of a pressurizedinert gas recirculation system in a gas enclosure system. First, undertypical operation of a gas enclosure system without a pressurized inertgas recirculation system, a gas enclosure system can be maintained at aslightly positive internal pressure relative to an external pressure inorder to safeguard against outside gas or air from entering the interiorshould any leaks develop in a gas enclosure system. For example, undertypical operation, for various embodiments of a gas enclosure system ofthe present teachings, the interior of a gas enclosure system can bemaintained at a pressure relative to the surrounding atmosphere externalto the enclosure system, for example, of at least 2 mbarg, for example,at a pressure of at least 4 mbarg, at a pressure of at least 6 mbarg, ata pressure of at least 8 mbarg, or at a higher pressure. Maintaining apressurized inert gas recirculation system within a gas enclosure systemcan be challenging, as it presents a dynamic and ongoing balancing actregarding maintaining a slight positive internal pressure of a gasenclosure system, while at the same time continuously introducingpressurized gas into a gas enclosure system. Further, variable demand ofvarious devices and apparatuses can create an irregular pressure profilefor various gas enclosure assemblies and systems of the presentteachings. Maintaining a dynamic pressure balance for a gas enclosuresystem held at a slight positive pressure relative to the externalenvironment under such conditions can provide for the integrity of anongoing OLED printing process.

For various embodiments of a gas enclosure system, a pressurized inertgas recirculation system according to the present teachings can includevarious embodiments of a pressurized inert gas loop that can utilize atleast one of a compressor, an accumulator, and a blower, andcombinations thereof. Various embodiments of a pressurized inert gasrecirculation system that include various embodiments of a pressurizedinert gas loop can have a specially designed pressure-controlled bypassloop that can provide internal pressure of an inert gas in a gasenclosure system of the present teachings at a stable, defined value. Invarious embodiments of a gas enclosure system, a pressurized inert gasrecirculation system can be configured to recirculate pressurized inertgas via a pressure-controlled bypass loop when a pressure of an inertgas in an accumulator of a pressurized inert gas loop exceeds a pre-setthreshold pressure. The threshold pressure can be, for example, within arange from between about 25 psig to about 200 psig, or more specificallywithin a range of between about 75 psig to about 125 psig, or morespecifically within a range from between about 90 psig to about 95 psig.In that regard, a gas enclosure system of the present teachings having apressurized inert gas recirculation system with various embodiments of aspecially designed pressure-controlled bypass loop can maintain abalance of having a pressurized inert gas recirculation system in anhermetically sealed gas enclosure.

According to the present teachings, various devices and apparatuses canbe disposed in the interior and in fluid communication with variousembodiments of a pressurized inert gas recirculation system havingvarious pressurized inert gas loops that can utilize a variety ofpressurized gas sources, such as at least one of a compressor, a blower,and combinations thereof. For various embodiments of a gas enclosure andsystem of the present teachings, the use of various pneumaticallyoperated devices and apparatuses can be provide low-particle generatingperformance, as well as being low maintenance. Exemplary devices andapparatuses that can be disposed in the interior of a gas enclosuresystem and in fluid communication with various pressurized inert gasloops can include, for example, but not limited by, one or more of apneumatic robot, a substrate floatation table, an air bearing, an airbushing, a compressed gas tool, a pneumatic actuator, and combinationsthereof. A substrate floatation table, as well as air bearings can beused for various aspects of operating an OLED printing system inaccordance with various embodiments of a gas enclosure system of thepresent teachings. For example, a substrate floatation table utilizingair-bearing technology can be used to transport a substrate intoposition in a printhead chamber, as well as to support a substrateduring an OLED printing process.

FIG. 1A is a right, front perspective view of gas enclosure assembly 100according to various embodiments of the present teachings. Gas enclosureassembly 100 can be integrated with various components to provide forvarious embodiments of a gas enclosure system of the present teachings.A gas enclosure system of the present teachings can contain one or moregases for maintaining an inert environment in a gas enclosure assemblyinterior, as well as components for maintaining a substantiallylow-particle environment. By way of non-limiting examples, variousembodiments of a gas enclosure system can have a particle control systemthat can include a gas circulation and filtration system, as well as,purification components for removing reactive species from recirculatedinert gas, and can have various embodiments of a pressurized inert gasrecirculation system. As such, various embodiments of a gas enclosuresystem of the present teachings can be useful in maintaining an inert,substantially low-particle gas atmosphere in the interior.

For example, FIG. 1B is a left front perspective view of variousembodiments of gas enclosure system 500. FIG. 1B depicts gas enclosuresystem 500, which can include various embodiments of gas enclosureassembly 100. Gas enclosure system 500 can have load-locked inletchamber 1110, which can have inlet gate 1112. Gas enclosure system 500of FIG. 1B can include a gas purification system 3130 for providing gasenclosure assembly 100 with a constant supply of inert gas havingsubstantially low levels of reactive atmospheric species, such as watervapor and oxygen, as well as organic solvent vapors that result from anOLED printing process. According to the present teachings, an inert gasmay be any gas that does not undergo a chemical reaction under a definedset of conditions. Some commonly used non-limiting examples of an inertgas can include nitrogen, any of the noble gases, and any combinationthereof. Various embodiments of a gas purification system according tothe present teachings, such as gas purification system 3130 of FIG. 1B,can maintain levels for each species of various reactive species,including various reactive atmospheric gases, such as water vapor andoxygen, as well as organic solvent vapors at 100 ppm or lower, forexample, at 10 ppm or lower, at 1.0 ppm or lower, or at 0.1 ppm orlower.

Gas enclosure system 500 of FIG. 1B can also have controller system 1130for system control functions. For example, system controller 1130 caninclude one or more processor circuits (not shown) in communication withone or more memory circuits (not shown). System controller 1130 can alsocommunicate with a load-locked inlet chamber 1110, an outlet chamber(not shown) and ultimately with a print nozzle of an OLED printingsystem, which can be housed in gas enclosure system 500. In this manner,system controller 1130 can coordinate, for example, the opening of gates1112 in load-locked inlet chamber 1110, to allow the entry of asubstrate into gas enclosure system 500. System controller 1130 cancontrol a variety of system functions, such as controlling inkdispensing to a print nozzle of an OLED printing system. Gas enclosuresystem 500 of FIG. 1B is configured to encompass and protect anair-sensitive process, such as the printing of a variety of inks usefulfor creating an OLED stack using an industrial printing system. Examplesof atmospheric gases that are reactive to OLED inks include water vaporand oxygen, as well as a variety of organic vapors from organic solventsused, for example, as carriers for various OLED inks. As previouslydiscussed herein, gas enclosure assembly 100 can be configured tomaintain a sealed atmosphere and allow a component or a printing systemto operate effectively while gas enclosure system 500 can provide allcomponents necessary for maintaining an inert environment. Additionally,gas enclosure 500 can have a particle control system providing alow-particle zone proximal to a substrate that can include componentssuch as, by way of non-limiting examples, a gas circulation andfiltration system, a low-particle-generating X-axis linear bearingsystem for moving a printhead assembly relative to a substrate, aservice bundle housing exhaust system, and a printhead assembly exhaustsystem.

As depicted in FIG. 1A, various embodiments of gas enclosure assembly100 can comprise component parts including a front or first wall panel210′, a left, or second wall panel (not shown), a right or third wallpanel 230′, a back or forth wall panel (not shown), and ceiling panel250′, which gas enclosure assembly can be attached to pan 204, whichrests on a base (not shown). As will be discussed in more detailsubsequently herein, various embodiments of a gas enclosure assembly 100of FIG. 1A can be constructed from a front or first wall frame 210, aleft, or second wall frame (not shown), a right or third wall frame 230,a back or forth wall panel (not shown), and a ceiling frame 250. Variousembodiments of a ceiling frame 250 can include a fan filter unit cover103, as well as first ceiling frame duct 105, and first ceiling frameduct 107. According to embodiments of the present teachings, varioustypes of section panels may be installed in any of a plurality of panelsection comprising a frame member. In various embodiments of gasenclosure 100 of FIG. 1 , sheet metal panel sections 109 can be weldedinto a frame member during the construction of a frame. For variousembodiments of gas enclosure assembly 100, types of section panels canthat can be repeatedly installed and removed through cycles ofconstruction and deconstruction of a gas enclosure assembly can includean inset panel 110, as indicated for wall panel 210′, as well as awindow panel 120 and readily-removable service window 130, as indicatedfor wall panel 230′.

Though readily-removable service window 130 can provide ready access tothe interior of enclosure 100, any panel that is removable can be usedto provide access to the interior of a gas enclosure system for thepurpose of repair and regular service. Such access for service or repairis differentiated from the access provided by panels such as windowpanel 120 and readily-removable service window 130, which can provide anend-user glove access to the interior of a gas enclosure assembly duringuse from the exterior of a gas enclosure assembly. For example, any ofthe gloves, such as glove 142, which is attached to gloveport 140, asshown in FIG. 1A for panel 230, can provide an end-user access to theinterior during use of a gas enclosure system.

FIG. 2 depicts an exploded view of various embodiments of a gasenclosure assembly as depicted in FIG. 1A. Various embodiments of a gasenclosure assembly can have a plurality of wall panels, includingoutside perspective view of front wall panel 210′, outside perspectiveview of left wall panel 220′, interior perspective view of a right wallpanel 230′, interior perspective view of rear wall panel 240′, and topperspective view of ceiling panel 250′, which as shown in FIG. 1A can beattached to pan 204, which rests upon base 202. An OLED printing systemcan mounted on top of pan 204, which printing processes are known to besensitive to atmospheric conditions. According to the present teachings,a gas enclosure assembly can be constructed from frame members, forexample, wall frame 210 of wall panel 210′, wall frame 220 of wall panel220′, wall frame 230 of wall panel 230′, wall frame 240 of wall panel240′, and ceiling frame 250 of ceiling panel 250′, in which a pluralityof section panels can then be installed. In that regard, it can bedesirable to streamline the design of section panels that can berepeatedly installed and removed through cycles of construction anddeconstruction of various embodiments of a gas enclosure assembly of thepresent teachings. Moreover, contouring of a gas enclosure assembly 100can be done to accommodate a footprint of various embodiments of an OLEDprinting system in order to minimize the volume of inert gas required ina gas enclosure assembly, as well as providing ready access to anend-user; both during use of a gas enclosure assembly, as well as duringmaintenance.

Using front wall panel 210′ and left wall panel 220′ as exemplary,various embodiments of a frame member can have sheet metal panelsections 109 welded into a frame member during frame memberconstruction. Inset panel 110, window panel 120 and readily-removableservice window 130 can be installed in each of a wall frame member, andcan be repeatedly installed and removed through cycles of constructionand deconstruction of gas enclosure assembly 100 of FIG. 2 . As can beseen; in the example of wall panel 210′ and wall panel 220′, a wallpanel can have a window panel 120 proximal to a readily-removableservice window 130. Similarly, as depicted in the example rear wallpanel 240′, a wall panel can have a window panel such as window panel125, which has two adjacent gloveports 140. For various embodiments ofwall frame members according to the present teachings, and as seen forgas enclosure assembly 100 of FIG. 1A, such an arrangement of glovesprovides easy access from the exterior of a gas enclosure to componentparts within an enclosed system. Accordingly, various embodiments of agas enclosure can provide two or more gloveports so that an end-user canextend a left glove and a right glove into the interior and manipulateone or more items in the interior, without disturbing the composition ofthe gaseous atmosphere within the interior. For example, any of windowpanel 120 and service window 130 can be positioned to facilitate easyaccess from the exterior of a gas enclosure assembly to an adjustablecomponent in the interior of a gas enclosure assembly. According tovarious embodiments of a window panel, such as window panel 120 andservice window 130, when end-user access through a gloveport glove isnot indicated, such windows may not include a gloveport and gloveportassembly.

Various embodiments of wall and ceiling panels, as depicted in FIG. 2 ,can have a plurality of an inset panel 110. As can be seen in FIG. 2 ,inset panels can have a variety of shapes and aspect ratios. In additionto inset panels, ceiling panel 250′ can have a fan filter unit cover 103as well as first ceiling frame duct 105, and second ceiling frame duct107, mounted, bolted, screwed, fixed, or otherwise secured to ceilingframe 250. As will be discussed in more detail subsequently herein,ductwork in fluid communication with duct 107 of ceiling panel 250′ canbe installed within the interior of a gas enclosure assembly. Accordingto the present teachings, such ductwork can be part of a gas circulationsystem internal to a gas enclosure assembly, as well as providing forseparating the flow stream exiting a gas enclosure assembly forcirculation through at least one gas purification component external toa gas enclosure assembly.

FIG. 3 is an exploded front perspective view of frame member assembly200, in which wall frame 220 can be constructed to include a completecomplement of panels. Though not limited to the design shown, framemember assembly 200, using wall frame 220, can be used as exemplary forvarious embodiments of a frame member assembly according to the presentteachings. Various embodiments of a frame member assembly can becomprised of various frame members and section panels installed invarious frame panel sections of various frame members according to thepresent teachings.

According to various embodiments of various frame member assemblies ofthe present teachings, frame member assembly 200 can be comprised of aframe member, such as wall frame 220. For various embodiments of a gasenclosure assembly, such as gas enclosure assembly 100 of FIG. 1A,processes that may utilize equipment housed in such a gas enclosureassembly may not only require an hermetically sealed enclosure providingan inert environment, but an environment substantially free ofparticulate matter. In that regard, a frame member according to thepresent teachings may utilize variously dimensioned metal tube materialsfor the construction of various embodiments of a frame. Such metal tubematerials address desired material attributes, including, but notlimited by, a high-integrity material that will not degrade to produceparticulate matter, as well as producing a frame member having highstrength, yet optimal weight, providing for ready transport,construction, and deconstruction from one site to another site of a gasenclosure assembly comprising various frame members and panel sections.According to the present teachings, any material satisfying theserequirements can be utilized for creating various frame membersaccording to the present teachings.

For example, various embodiments of a frame member according to thepresent teachings, such as frame member assembly 200, can be constructedfrom extruded metal tubing. According to various embodiments of a framemember, aluminum, steel, and a variety of metal composite materials maybe utilized for constructing a frame member. In various embodiments,metal tubing having dimensions of, for example, but not limited by,2″w×2″h, 4″w×2″h and 4″w×4″h and having ⅛″ to ¼″ wall thickness can beused to construct various embodiments of frame members according to thepresent teachings. Additionally, a variety of reinforced fiber polymericcomposite materials of a variety of tube or other forms are availablethat have the material attributes including, but not limited by, ahigh-integrity material that will not degrade to produce particulatematter, as well as producing a frame member having high strength, yetoptimal weight, providing for ready transport, construction, anddeconstruction from one site to another site.

Regarding construction of various frame members from variouslydimensioned metal tube materials, it is contemplated that welding tocreate various embodiments of frame weldments can be done. Additionally,construction of various frame members from variously dimensionedbuilding materials can be done using an appropriate industrial adhesive.It is contemplated that the construction of various frame members shouldbe done in a fashion that would not intrinsically create leak pathsthrough a frame member. In that regard, construction of various framemembers can be done using any approach that does not intrinsicallycreate leak paths through a frame member for various embodiments of agas enclosure assembly. Further, various embodiments of frame membersaccording to the present teachings, such as wall frame 220 of FIG. 2 ,may be painted or coated. For various embodiments of a frame member madefrom a metal tubing material prone, for example, to oxidation, wherematerial formed at the surface may create particulate matter, paintingor coating, or other surface treatment, such as anodizing, to preventthe formation of particulate matter can be done.

A frame member assembly, such as frame member assembly 200 of FIG. 3 ,can have a frame member, such as wall frame 220. Wall frame 220 can havetop 226, upon which a top wall frame spacer plate 227 can be fastened,as well as a bottom 228, upon which a bottom wall frame spacer plate 229can be fastened. As will be discussed in more detail subsequentlyherein, spacer plates mounted on surfaces of a frame member are a partof a gasket sealing system, which in conjunction with the gasket sealingof panels mounted in frame member sections, provides for hermeticsealing of various embodiments of a gas enclosure assembly according tothe present teachings. A frame member, such as wall frame 220 of framemember assembly 200 of FIG. 3 , can have several panel frame sections,where each section can be fabricated to receive various types of panels,such as, but not limited by, an inset panel 110, a window panel 120 anda readily-removable service window 130. Various types of panel sectionscan be formed in the construction of a frame member. Types of panelsections can include, for example, but not limited by, an inset panelsection 10, for receiving inset panel 110, a window panel section 20,for receiving window panel 120, and a service window panel section 30,for receiving readily-removable service window 130.

Each type of panel section can have a panel section frame to receive apanel, and can provide that each panel can be sealably fastened intoeach panel section in accordance with the present teachings forconstructing an hermetically sealed gas enclosure assembly. For example,in FIG. 3 depicting a frame assembly according to the present teachings,inset panel section 10 is shown to have frame 12, window panel section20 is shown to have frame 22, and service window panel section 30 isshown to have frame 32. For various embodiments of a wall frame assemblyof the present teachings, various panel section frames can be a metalsheet material welded into the panel sections with a continuousweld-bead to provide a hermetic seal. For various embodiments of a wallframe assembly, various panel section frames can be made from a varietyof sheet materials, including building materials selected fromreinforced fiber polymeric composite materials, which can be mounted ina panel section using an appropriate industrial adhesive. As will bediscussed in more detail in subsequent teachings concerning sealing,each panel section frame can have a compressible gasket disposed thereonto ensure that a gas-tight seal can be formed for each panel installedand fastened in each panel section. In addition to a panel sectionframe, each frame member section can have hardware related topositioning a panel, as well as to securely fastening a panel in a panelsection.

Various embodiments of inset panel 110 and panel frame 122 for windowpanel 120 can be constructed from sheet metal material, such as, but notlimited by, aluminum, various alloys of aluminum and stainless steel.The attributes for the panel material can be the same as they are forthe structural material constituting various embodiments of framemembers. In that regard, materials having attributes for various panelmembers include, but not are limited by, a high integrity material thatwill not degrade to produce particulate matter, as well as producing apanel having high strength, yet optimal weight, in order to provide forready transport, construction, and deconstruction from one site toanother site. Various embodiments of, for example, honeycomb core sheetmaterial can have the requisite attributes for use as panel material forconstruction of inset panel 110 and panel frame 122 for window panel120. Honeycomb core sheet material can be made of a variety ofmaterials; both metal, as well as metal composite and polymeric, as wellas polymer composite honeycomb core sheet material. Various embodimentsof removable panels when fabricated from a metal material can haveground connections included in the panel to ensure that when a gasenclosure assembly is constructed that the entire structure is grounded.

Given the transportable nature of components used to construct a gasenclosure assembly of the present teachings, any of the variousembodiments of section panels of the present teachings can be repeatedlyinstalled and removed during use of a gas enclosure system to provideaccess to the interior of a gas enclosure assembly.

For example, panel section 30 for receiving a readily-removable servicewindow panel 130 can have a set of four spacers, of which one isindicated as window guide spacer 34. Additionally, panel section 30,which is constructed for receiving a readily-removable service windowpanel 130, can have a set of four clamping cleats 36, which can be usedto clamp service window 130 into service window panel section 30 using aset of four of a reverse acting toggle clamp 136 mounted on servicewindow frame 132 for each of a readily removable service window 130.Further, two of each of a window handle 138 can be mounted onreadily-removable service window frame 132 to provide an end-user easeof removal and installation of service window 130. The number, type, andplacement of removable service window handles can be varied.Additionally, service window panel section 30 for receiving areadily-removable service window panel 130 can have at least two of awindow clamp 35, selectively installed in each service window panelsection 30. Though depicted as in the top and bottom of each of servicewindow panel section 30, at least two window clamps can be installed inany fashion that acts to secure service window 130 in panel sectionframe 32. A tool can be used to remove and install window clamp 35, inorder to allow service window 130 to be removed and reinstalled.

Reverse acting toggle clamp 136 of service window 130, as well ashardware installed on panel section 30, including clamping cleat 36,window guide spacer 34, and window clamp 35, can be constructed of anysuitable material, as well as combination of materials. For example, oneor more such elements can comprise at least one metal, at least oneceramic, at least one plastic, and a combination thereof. Removableservice window handle 138 can be constructed of any suitable material,as well as a combination of materials. For example, one or more suchelements can comprise at least one metal, at least one ceramic, at leastone plastic, at least one rubber, and a combination thereof. Enclosurewindows, such as window 124 of window panel 120, or window 134 ofservice window 130, can comprise any suitable material as well as acombination of materials. According to various embodiments of a gasenclosure assembly of the present teachings, enclosure windows cancomprise a transparent and a translucent material. In variousembodiments of a gas enclosure assembly, enclosure windows can comprisesilica-based materials, for example, but not limited by, such as glassand quartz, as well as various types of polymeric-based materials, forexample, but not limited by, such as various classes of polycarbonate,acrylic, and vinyl. According to systems and methods of the presentteachings, transparent and translucent properties of various compositesand combinations thereof are desirable attributes for exemplary windowmaterials.

As will be discussed in the following teachings for FIGS. 8A-9B, walland ceiling frame member seals in conjunction with gas-tight sectionpanel frame seals together provide for various embodiments of anhermetically-sealed gas enclosure assembly for air-sensitive processesthat require an inert environment. Components of a gas enclosure systemthat contribute to providing substantially low concentrations ofreactive species, as well as substantially low particulate environmentcan include, but are not limited by, an hermetically sealed gasenclosure assembly, as well as a highly effective gas circulation andparticle filtration system, including ductwork. Providing effectivehermetic seals for a gas enclosure assembly can be challenging;especially where three frame members come together to form a three-sidedjoint. As such, three-sided joint sealing presents a particularlydifficult challenge with respect to providing readily-installablehermetic sealing for a gas enclosure assembly that can be assembled anddisassembled through cycles of construction and deconstruction.

In that regard, various embodiments of a gas enclosure assemblyaccording to the present teachings provide for hermetic sealing of afully-constructed gas enclosure system through effective gasket sealingof joints, as well as providing effective gasket sealing around loadbearing building components. Unlike conventional joint sealing, jointsealing according to the present teachings: 1) includes uniform parallelalignment of abutted gasket segments from orthogonally oriented gasketlengths at top and bottom terminal frame joint junctures where threeframe members are joined, thereby avoiding angular seam alignment andsealing, 2) provides for forming the abutted lengths across an entirewidth of a joint, thereby increasing the sealing contact area atthree-sided joint junctures, 3) is designed with spacer plates thatprovide uniform compression force across all vertical, and horizontal,as well as top and bottom three-sided joint gasket seals. Additionally,the selection of the gasket material can impact the effectiveness ofproviding an hermetic seal, which will be discussed subsequently herein.

FIG. 4A through FIG. 4C are top schematic views that depict a comparisonof conventional three-sided joint seals to three-sided joint sealsaccording to the present teachings. According to various embodiments ofa gas enclosure assembly the present teachings, there can be, forexample, but not limited by, at least four wall frame members, a ceilingframe member and a pan, that can be joined to form a gas enclosureassembly, creating a plurality of vertical, horizontal, and three-sidedjoints requiring hermetic sealing. In FIG. 4A, a top schematic view of aconventional three-sided gasket seal formed from a first gasket I, whichis orthogonally oriented to gasket II in the X-Y plane. As shown in FIG.4A, a seam formed from the orthogonal orientation in the X-Y plane has acontact length W₁ between the two segments defined by the dimension ofwidth of the gasket. Additionally, a terminal end portion of gasket III,which is a gasket orthogonally oriented to both gasket I and gasket IIin the vertical direction, can abut gasket I and gasket II, as indicatedby the hatching. In FIG. 4B, a top schematic view of a conventionalthree-sided joint gasket seal formed from a first gasket length I, whichis orthogonal to a second gasket length II, and has a seam joining 45°faces of both lengths, where the seam has a contact length W₂ betweenthe two segments that is greater than the width of the gasket material.Similarly to the configuration of FIG. 4A, an end portion of gasket III,which is orthogonal to both gasket I and gasket II in the verticaldirection can abut gasket I and gasket II, as indicated by the hatching.Assuming that the gaskets widths are the same in FIG. 4A and FIG. 4B,the contact length W₂ for FIG. 4B is greater than the contact length W₁for FIG. 4A.

FIG. 4C is a top schematic view of a three-sided joint gasket sealaccording to the present teachings. A first gasket length I can have agasket segment I′ formed orthogonally to the direction of gasket lengthI, where gasket segment I′ has a length that can be approximately thedimension of the width of a structural component being joined, such as a4″w×2″h or 4″w×4″h metal tube used to form various wall frame members ofa gas enclosure assembly of the present teachings. Gasket II isorthogonal to gasket I in the X-Y plane, and has gasket segment II′,which has an overlapping length with gasket segment I′ that isapproximately the width of structural components being joined. The widthof gasket segments I′ and II′ are the width of a compressible gasketmaterial selected. Gasket III is orthogonally oriented to both gasket Iand gasket II in the vertical direction. Gasket segment III′ is an endportion of gasket III. Gasket segment III′ is formed from the orthogonalorientation of gasket segment III′ to the vertical length of gasket III.Gasket segment III′ can be formed so that it has approximately the samelength as gasket segments I′ and II′, and a width that is the thicknessof a compressible gasket material selected. In that regard, the contactlength W₃ for the three aligned segments shown in FIG. 4C is greaterthan for the conventional three-corner joint seals shown in either FIG.4A or FIG. 4B, having contact length W₁ and W₂, respectively.

In that regard, three-sided joint gasket sealing according to thepresent teachings creates uniform parallel alignment of gasket segmentsat terminal joint junctures from what would otherwise be orthogonallyaligned gaskets, as shown in the case of FIG. 4A and FIG. 4B. Suchuniform parallel alignment of the three-sided joint gasket sealingsegments provides for applying a uniform lateral sealing force acrossthe segments to promote an hermetic three-sided joint seal at the topand bottom corners of joints formed from wall frame members.Additionally, each segment of the uniformly aligned gasket segments foreach three-sided joint seal is selected to be approximately the width ofthe structural components being joined, providing for a maximum lengthof contact of the uniformly aligned segments. Moreover, joint sealingaccording to the present teachings is designed with spacer plates thatprovide a uniform compression force across all vertical, horizontal, andthree-sided gasket seals of a building joint. It may be argued that thewidth of the gasket material selected for conventional three-sided sealsgiven for the examples of FIGS. 6A and 6B could be at least the width ofstructural components being joined.

The exploded perspective view of FIG. 5A, depicts sealing assembly 300according to the present teachings before all frame members have beenjoined, so that the gaskets are depicted in an uncompressed state. InFIG. 5A, a plurality of wall frame members, such as wall frame 310, wallframe 350, as well as ceiling frame 370 can be sealably joined in afirst step of the construction of a gas enclosure from variouscomponents of a gas enclosure assembly. Frame member sealing accordingto the present teachings is a substantial part of providing that a gasenclosure assembly once fully constructed is hermetically sealed, aswell as providing sealing that can be implemented through cycles ofconstruction and deconstruction of a gas enclosure assembly. Though theexample given in the following teachings for FIGS. 7A-7B are for thesealing of a portion of a gas enclosure assembly, such teachings applyto the entirety of any of a gas enclosure assembly of the presentteachings.

First wall frame 310 depicted in FIG. 5A can have interior side 311 onwhich spacer plate 312 is mounted, vertical side 314, and top surface315 on which spacer plate 316 is mounted. First wall frame 310 can havefirst gasket 320 disposed in and adhered to a space formed from spacerplate 312. Gap 302, remaining after first gasket 320 is disposed in andadhered to a space formed from spacer plate 312, can run a verticallength of first gasket 320, as shown in FIG. 5A. As depicted in FIG. 5A,compliant gasket 320 can be disposed in and adhered to the space formedfrom spacer plate 312, and can have vertical gasket length 321,curvilinear gasket length 323, and gasket length 325 that is formed 90°in plane to vertical gasket length 321 on interior frame member 311 andterminates at vertical side 314 of wall frame 310. In FIG. 5A, firstwall frame 310 can have top surface 315 on which spacer plate 316 ismounted, thereby forming a space on surface 315 on which second gasket340 is disposed in and adhered to proximal to inner edge 317 of wallframe 310. Gap 304, remaining after second gasket 340 is disposed in andadhered to a space formed from spacer plate 316, can run a horizontallength of second gasket 340, as shown in FIG. 5A. Further, as indicatedby the hatched line, length 345 of gasket 340 is uniformly parallel andcontiguously aligned with length 325 of gasket 320.

Second wall frame 350 depicted in FIG. 5A can have exterior frame side353, vertical side 354, and top surface 355 on which spacer plate 356 ismounted. Second wall frame 350 can have first gasket 360 disposed in andadhered to first gasket a space, which is formed from spacer plate 356.Gap 306, remaining after first gasket 360 is disposed in and adhered toa space formed from spacer plate 356, can run a horizontal length offirst gasket 360, as shown in FIG. 5A. As depicted in FIG. 5A, compliantgasket 360 can have horizontal length 361, curvilinear length 363, andlength 365 that is formed 90° in plane on top surface 355 and terminatesat exterior frame member 353.

As indicated in the exploded perspective view of FIG. 5A, interior framemember 311 of wall frame 310 can be joined to vertical side 354 of wallframe 350 to form one building joint of a gas enclosure frame assembly.Regarding the sealing of a building joint so formed, in variousembodiments of gasket sealing at terminal joint junctures of wall framemembers according to the present teachings as depicted in FIG. 5A,length 325 of gasket 320, length 365 of gasket 360 and length 345 ofgasket 340 are all contiguously and uniformly aligned. Additionally, aswill be discussed in more detail subsequently herein, variousembodiments of a spacer plate of the present teachings can provide for auniform compression of between about 20% to about 40% deflection of acompressible gasket material used for hermetically sealing variousembodiments of a gas enclosure assembly of the present teachings.

FIG. 5B depicts sealing assembly 300 according to the present teachingsafter all frame members have been joined, so that the gaskets aredepicted in a compressed state. FIG. 5B is perspective view that showsthe detail of corner seal of a three-sided joint formed at the topterminal joint juncture between first wall frame 310, second wall frame350 and ceiling frame 370; which is shown in phantom view. As shown inFIG. 5B, the gasket spaces defined by the spacer plates can bedetermined to be a width, such that upon joining wall frame 310, wallframe 350 and ceiling frame 370; shown in phantom view, a uniformcompression of between about 20% to about 40% deflection of acompressible gasket material for forming vertical, horizontal, andthree-sided gasket seals ensures that gasket sealing at all surfacessealed at joints of wall frame members can provide hermetic sealing.Additionally gasket gaps 302, 304, and 306 (not shown) are dimensioned,so that upon optimal compression of between about 20% to about 40%deflection of a compressible gasket material, each gasket can fill agasket gap as shown for gasket 340 and gasket 360 in FIG. 5B. As such,in addition to providing uniform compression by defining a space inwhich each gasket is disposed in and adhered to, various embodiments ofa spacer plate designed to provide a gap also ensure that eachcompressed gasket can conform within the spaces defined by a spacerplate without wrinkling or bulging or otherwise irregularly forming in acompressed state in a fashion that could form leak paths.

According to various embodiments of a gas enclosure assembly of thepresent teachings, various types of section panels can be sealed usingcompressible gasket material disposed on each of a panel section frame.In conjunction with the frame member gasket sealing, the locations andmaterials of the compressible gaskets used to form seals between thevarious section panels and panel section frames can provide for anhermetically sealed gas enclosure assembly with little or no gasleakage. Additionally, the sealing design for all types of panels, suchas inset panel 110, window panel 120 and readily-removable servicewindow 130 of FIG. 3 , can provide for durable panel sealing afterrepeated removal and installation of such panels that may be required asto access the interior of a gas enclosure assembly, for example, formaintenance.

For example, FIG. 6A, is an exploded view depicting service window panelsection 30, and readily-removable service window 130. As previouslydiscussed herein, service window panel section 30 can be fabricated forreceiving readily-removable service window 130. For various embodimentsof a gas enclosure assembly, a panel section, such as removable servicepanel section 30, can have panel section frame 32, as well ascompressible gasket 38 disposed on panel section frame 32. In variousembodiments, hardware related to fastening readily-removable servicewindow 130 in removable service window panel section 30 can provide easeof installation and reinstallation to an end-user, and at the same timeensure that a gas-tight seal is maintained when readily-removableservice window 130 is installed and reinstalled in panel section 30 asneeded by an end-user requiring direct access to the interior of a gasenclosure assembly. Readily-removable service window 130 can includerigid window frame 132, which can be constructed from, for example, butnot limited by, a metal tube material as described for constructing anyof the frame members of the present teachings. Service window 130 canutilize quick-acting fastening hardware, for example, but not limited byreverse acting toggle clamp 136 in order to provide an end-user readyremoval and reinstallation of service window 130.

As shown in front view of removable service window panel section 30 ofFIG. 6A, readily-removable service window 130 can have a set of fourtoggle clamps 136 secured on window frame 132. Service window 130 can bepositioned into panel section frame 30 at a defined distance forinsuring a proper compression force against gasket 38. Using a set offour window guide spacers 34, as shown in FIG. 6B, of which can beinstalled in each corner of panel section 30 for positioning servicewindow 130 in panel section 30. A set of each of a clamping cleat 36 canbe provided to receive reverse acting toggle clamp 136 of readilyremovable service window 136. According to various embodiments for thehermetic sealing of service window 130 through cycles of installationand removal, the combination of the mechanical strength of servicewindow frame 132, in conjunction with the defined position of servicewindow 130 provided by a set of window guide spacers 34 with respect tocompressible gasket 38 can ensure that once service window 130 issecured in place with, for example, but not limited by, using reverseaction toggle clamps 136 fastened in respective clamping cleats 36,service window frame 132 can provide an even force over panel sectionframe 32 with defined compression as set by a set of window guidespacers 34. The set of window guide spacers 34 are positioned so thatthe compression force of window 130 on gasket 38 deflects compressiblegasket 38 between about 20% to about 40%. In that regard, theconstruction of service window 130, as well as fabrication of panelsection 30 provide for a gas-tight seal of service window 130 in panelsection 30. As previously discussed herein, window clamps 35 can beinstalled into panel section 30 after service window 130 is fastenedinto panel section 30, and removed when service window 130 needs to beremoved.

Reverse acting toggle clamp 136 can be secured to a readily-removableservice window frame 132 using any suitable means, as well as acombination of means. Examples of suitable securing means that can beused include at least one adhesive, for example, but not limited by anepoxy, or a cement, at least one bolt, at least one screw, at least oneother fastener, at least one slot, at least one track, at least oneweld, and a combination thereof. Reverse acting toggle clamp 136 can bedirectly connected to removable service window frame 132 or indirectlythrough an adaptor plate. Reverse acting toggle clamp 136, clampingcleat 36, window guide spacer 34, and window clamp 35 can be constructedof any suitable material, as well as a combination of materials. Forexample, one or more such elements can comprise at least one metal, atleast one ceramic, at least one plastic, and a combination thereof.

In addition to sealing a readily-removable service window, gas-tightsealing can also be provided for inset panels and window panels. Othertypes of section panels that can be repeatedly installed and removed inpanel sections include, for example, but not limited by, inset panels110 and window panels 120, as shown in FIG. 3 . As can be seen in FIG. 3, panel frame 122 of window panel 120 is constructed similarly to insetpanel 110. As such, according to various embodiments of a gas enclosureassembly, the fabrication of panel sections for receiving inset panelsand window panels can be the same. In that regard, the sealing of insetpanels and window panel can be implemented using the same principles.

With reference to FIG. 7A and FIG. 7B, and according to variousembodiments of the present teachings, any of the panels of gasenclosure, such as gas enclosure assembly 100 of FIG. 1 , can includeone or more inset panel sections 10, which can have frames 12 configuredto receive a respective inset panel 110. FIG. 7A is a perspective viewindicating an enlarged portion shown in FIG. 9B. In FIG. 7A inset panel110 is depicted positioned with respect to inset frame 12. As can beseen in FIG. 7B, inset panel 110 is affixed to frame 12, where frame 12can be, for example, constructed of a metal. In some embodiments, themetal can comprise aluminum, steel, copper, stainless steel, chromium,an alloy, and combinations thereof, and the like. A plurality of a blindtapped hole 14 can be made in inset panel section frame 12. Panelsection frame 12 is constructed so as to comprise a gasket 16 betweeninset panel 110 and frame 12, in which compressible gasket 18 can bedisposed. Blind tapped hole 14 can be of the M5 variety. Screw 15 can bereceived by blind tapped hole 14, compressing gasket 16 between insetpanel 110 and frame 12. Once fastened into place against gasket 16,inset panel 110 forms a gas-tight seal within inset panel section 10. Aspreviously discussed herein, such panel sealing can be implemented for avariety of section panels, including, but not limited by, inset panels110 and window panels 120, as shown in FIG. 3 .

According to various embodiments of compressible gaskets according tothe present teachings, compressible gasket material for frame membersealing and panel sealing can be selected from a variety of compressiblepolymeric materials, for example, but not limited by, any in the classof closed-cell polymeric materials, also referred to in the art asexpanded rubber materials or expanded polymer materials. Briefly, aclosed-cell polymer is prepared in a fashion whereby gas is enclosed indiscrete cells; where each discrete cell is enclosed by the polymericmaterial. Properties of compressible closed-cell polymeric gasketmaterials that are desirable for use in gas-tight sealing of frame andpanel components include, but are not limited by, that they are robustto chemical attack over a wide range of chemical species, possessexcellent moisture-barrier properties, are resilient over a broadtemperature range, and they are resistant to a permanent compressionset. In general, compared to open-cell-structured polymeric materials,closed-cell polymeric materials have higher dimensional stability, lowermoisture absorption coefficients, and higher strength. Various types ofpolymeric materials from which closed-cell polymeric materials can bemade include, for example, but not limited by, silicone, neoprene,ethylene-propylene-diene terpolymer (EPT); polymers and composites madeusing ethylene-propylene-diene-monomer (EPDM), vinyl nitrile,styrene-butadiene rubber (SBR), and various copolymers and blendsthereof.

The desirable material properties of closed-cell polymers are maintainedonly if the cells comprising the bulk material remain intact during use.In that regard, using such material in a fashion that can exceedmaterial specifications set for a closed-cell polymer, for example,exceeding the specification for use within a prescribed temperature orcompression range may cause degradation of a gasket seal. In variousembodiments of closed-cell polymer gaskets used for sealing framemembers and section panels in frame panel sections, compression of suchmaterials should not exceed between about 50% to about 70% deflection,and for optimal performance can be between about 20% to about 40%deflection.

In addition to close-cell compressible gasket materials, another exampleof a class of compressible gasket material having desired attributes foruse in constructing embodiments of a gas enclosure assembly according tothe present teachings includes the class of hollow-extruded compressiblegasket materials. Hollow-extruded gasket materials as a class ofmaterials have the desirable attributes, including, but not limited by,that they are robust to chemical attack over a wide range of chemicalspecies, possess excellent moisture-barrier properties, are resilientover a broad temperature range, and they are resistant to a permanentcompression set. Such hollow-extruded compressible gasket materials cancome in a wide variety of form factors, such as for example, but notlimited by, U-cell, D-cell, square-cell, rectangular-cell, as well asany of a variety of custom form factor hollow-extruded gasket materials.Various hollow-extruded gasket materials can be fabricated frompolymeric materials that are used for closed-cell compressible gasketfabrication. For example, but not limited by, various embodiments ofhollow-extruded gaskets can be fabricated from silicone, neoprene,ethylene-propylene-diene terpolymer (EPT); polymers and composites madeusing ethylene-propylene-diene-monomer (EPDM), vinyl nitrile,styrene-butadiene rubber (SBR), and various copolymers and blendsthereof. Compression of such hollow cell gasket materials should notexceed about 50% deflection in order to maintain the desired attributes.While the class of close-cell compressible gasket materials and theclass of hollow-extruded compressible gasket materials have been givenas examples, any compressible gasket material having the desiredattributes can be used for sealing structural components, such asvarious wall and ceiling frame members, as well as sealing variouspanels in panel section frames, as provided by the present teachings.

FIG. 8 is a bottom view of various embodiments of a ceiling panel of thepresent teaching, for example, such as ceiling panel 250′ of gasenclosure assembly 100 of FIG. 1A. According to various embodiments ofthe present teachings for the assembly of a gas enclosure, lighting canbe installed on the interior top surface of a ceiling panel, such asceiling panel 250′ of gas enclosure assembly 100 of FIG. 1A. As depictedin FIG. 8 , ceiling frame 250, having interior portion 251, can havelighting installed on the interior portion of various frame members. Forexample, ceiling frame 250 can have two ceiling frame sections 40, whichhave in common two ceiling frame beams 42 and 44. Each ceiling framesection 40 can have a first side 41, positioned towards the interior ofceiling frame 250, and a second side 43, positioned towards the exteriorof ceiling frame 250. For various embodiments according to the presentteaching of providing lighting for a gas enclosure, pairs of lightingelements 46 can be installed. Each pair of lighting elements 46 caninclude a first lighting element 45, proximal to first side 41 andsecond lighting element 47 proximal to second side 43 of a ceiling framesection 40. The number, positioning, and grouping of lighting elementsshown in FIG. 8 are exemplary. The number and grouping of lightingelements can be varied in any desired or suitable manner. In variousembodiments, the lighting elements can be mounted flat, while in otherembodiments that can be mounted so that they can be moved to a varietyof positions and angles. The placement of lighting elements is notlimited to the top panel ceiling 433 but can located, in addition or inthe alternative, on any other interior surface, exterior surface, andcombination of surfaces of gas enclosure assembly 100 shown in FIG. 1A.

The various lighting elements can comprise any number, type, orcombination of lights, for example, halogen lights, white lights,incandescent lights, arc lamps, or light emitting diodes or devices(LEDs). For example, each lighting element can comprise from 1 LED toabout 100 LEDs, from about 10 LEDs to about 50 LEDs, or greater than 100LEDs. LED or other lighting devices can emit any color or combination ofcolors in the color spectrum, outside the color spectrum, or acombination thereof. According to various embodiments of a gas enclosureassembly used for inkjet printing of OLED materials, as some materialsare sensitive to some wavelengths of light, a wavelength of light forlighting devices installed in a gas enclosure assembly can bespecifically selected to avoid material degradation during processing.For example, a 4X cool white LED can be used as can a 4X yellow LED orany combination thereof. An example of a 4X cool white LED is an LF1B-D4S-2THWW4 available from IDEC Corporation of Sunnyvale, Calif. Anexample of a 4X yellow LED that can be used is an LF1B-D4S-2SHY6 alsoavailable from IDEC Corporation. LEDs or other lighting elements can bepositioned or hung from any position on interior portion 251 of ceilingframe 250 or on another surface of a gas enclosure assembly. Lightingelements are not limited to LEDs. Any suitable lighting element orcombination of lighting elements can be used. FIG. 9 is a graph of anIDEC LED light spectra and shows the X-axis corresponding to intensitywhen peak intensity is 100% and the Y-axis corresponding to wavelengthin nanometers. Spectra for LF1 B yellow type, a yellow fluorescent lamp,a LF1B white type LED, a LF1B cool white type LED, and an LF1B red typeLED are shown. Other light spectra and combinations of light spectra canbe used in accordance with various embodiments of the present teachings.

Recalling, various embodiments of a gas enclosure assembly beconstructed in a fashion minimizes the internal volume of a gasenclosure assembly, and at the same time optimizes the working space toaccommodate various footprints of various OLED printing systems. Variousembodiments of a gas enclosure assembly so constructed additionallyprovide ready access to the interior of a gas enclosure assembly fromthe exterior during processing and readily access to the interior formaintenance, while minimizing downtime. In that regard, variousembodiments of a gas enclosure assembly according to the presentteachings can be contoured with respect to various footprints of variousOLED printing systems.

According to systems and methods of the present teachings, frame memberconstruction, panel construction, frame and panel sealing, as well asconstruction of a gas enclosure, such as gas enclosure 100 of FIG. 1A,can be applied to a gas enclosure of a variety of sizes and designs.Various embodiments of a gas enclosure assembly can have various framemembers that are constructed to provide contour for a gas enclosureassembly. Various embodiments of a gas enclosure assembly of the presentteachings can accommodate an OLED printing system, while optimizing theworking space to minimize inert gas volume, and also allowing readyaccess to an OLED printing system from the exterior during processing.In that regard, various gas enclosure assemblies of the presentteachings can vary in contoured topology and volume. As a non-limitingexample, various embodiments of a contoured gas enclosure according tothe present teachings can have a gas enclosure volume of between about 6m³ to about 95 m³ for housing various embodiments of a printing systemcapable of printing substrate sizes from Gen 3.5 to Gen 10. By way afurther non-limiting example, various embodiments of a contoured gasenclosure according to the present teachings can have a gas enclosurevolume of between about 15 m3 to about 30 m3 for housing variousembodiments of a printing system capable of printing, for example, Gen5.5 to Gen 8.5 substrate sizes. Such embodiments of a contoured gasenclosure can be between about 30% to about 70% savings in volume incomparison to a non-contoured enclosure having non-contoured dimensionsfor width, length and height.

Gas enclosure assembly 1000 of FIG. 9 can have all the features recitedin the present teachings for exemplary gas enclosure assembly 100 ofFIG. 1A. For example, but not limited by, gas enclosure assembly 1000can utilize the sealing according to the present teachings that providean hermetic-sealed enclosure through cycles of construction anddeconstruction. Various embodiments of a gas enclosure system based ongas enclosure assembly 1000 can have a gas purification system that canmaintain levels for each species of various reactive species, includingvarious reactive atmospheric gases, such as water vapor and oxygen, aswell as organic solvent vapors at 100 ppm or lower, for example, at 10ppm or lower, at 1.0 ppm or lower, or at 0.1 ppm or lower.

Additionally, as will be discussed in more detail subsequently herein,various embodiments of a gas enclosure system based on, for example, butnot limited by, gas enclosure assembly 100 of FIG. 1A and gas enclosureassembly 1000 of FIG. 9 can have a circulation and filtration systemthat can provide a laminar flow environment that can minimize turbulenceand can create a substantially low particle environment by maintainingairborne particulate levels meeting the standards of InternationalStandards Organization Standard (ISO) 14644-1:1999, as specified byClass 1 through Class 5. A determination of airborne particulate mattercan be performed for various embodiments of a gas enclosure systembefore a printing process for system validation, using, for example, aportable particle counting device. In various embodiments of a gasenclosure system, a determination of airborne particulate matter can beperformed as an ongoing quality check in situ while a substrate isprinted. For various embodiments of a gas enclosure system, adetermination of airborne particulate matter can be performed for systemvalidation before a substrate is printed and additionally in situ whilea substrate is printed.

Additionally, for various embodiments of a gas enclosure system of thepresent teachings, a substantially low-particle environment can providefor a substantially low-particle substrate surface. Modeling based onvarious embodiments of gas enclosure systems of the present teachingssuggests that without various particle control systems of the presentteachings, on-substrate deposition per print cycle per square meter ofsubstrate can be between more than about 1 million to more than about 10million particles for particles in a size range of 0.1

m and greater. Such calculations suggest that that without variousparticle control systems of the present teachings, on-substratedeposition per print cycle per square meter of substrate can be betweenmore than about 1000 to about more than about 10,000 particles forparticles in a size range of about 2 □m and greater. A determination ofan on-substrate distribution of particulate matter on a substrate can beperformed for various embodiments of a gas enclosure system before asubstrate is printed for system validation, using, for example, a testsubstrate. In various embodiments of a gas enclosure system, adetermination of an on-substrate distribution of particulate matter canbe performed as an ongoing quality check in situ while a substrate isprinted. For various embodiments of a gas enclosure system, adetermination of an on-substrate distribution of particulate matter canbe performed for system validation before a substrate is printed andadditionally in situ while a substrate is printed.

Various embodiments of a gas enclosure system can have a particlecontrol system that can maintain a substantially low-particleenvironment providing for an on-substrate particle specification forparticles of between about 0.1

m or greater to about 10

m or greater. Various embodiments of an on-substrate particlespecification can be readily converted from an average on-substrateparticle distribution per square meter of substrate per minute to anaverage on-substrate particle distribution per substrate per minute foreach of a target particle size range. As previously discussed herein,such a conversion can be readily done through a known relationshipbetween substrates, for example, of a specific generation-sizedsubstrate and the corresponding area for that substrate generation.Additionally, an average on-substrate particle distribution per squaremeter of substrate per minute can be readily converted to any of avariety of unit time expressions. For example, in addition toconversions between standard units of time; e.g. seconds, minutes, anddays, units of time specifically relating to processing can be used. Forexample, as previously discussed herein, a print cycle can be associatedwith a unit of time.

Various embodiments of a low-particle gas enclosure system of thepresent teachings can maintain a low-particle environment providing foran average on-substrate particle distribution that meets an on-substratedeposition rate specification of less than or equal to about 100particles per square meter of substrate per minute for particles greaterthan or equal to 10

m in size. Various embodiments of a low-particle gas enclosure system ofthe present teachings can maintain a low-particle environment providingfor an average on-substrate particle distribution that meets anon-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 5

m in size. In various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 2

m in size. In various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 1

m in size. Various embodiments of a low-particle gas enclosure system ofthe present teachings can maintain a low-particle environment providingfor an average on-substrate particle distribution that meets anon-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.5

m in size. For various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.3

m in size. Various embodiments of a low-particle gas enclosure system ofthe present teachings can maintain a low-particle environment providingfor an average on-substrate particle distribution that meets anon-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.1

m in size.

FIG. 9 depicts a perspective view gas enclosure assembly 1000 inaccordance with various embodiments of a gas enclosure assembly of thepresent teachings. Gas enclosure assembly 1000 can include front panelassembly 1200′, middle panel assembly 1300′ and rear panel assembly1400′. Front panel assembly 1200′ can include front ceiling panelassembly 1260′, front wall panel assembly 1240′, which can have opening1242 for receiving a substrate, and front base panel assembly 1220′.Rear panel assembly 1400′ can include rear ceiling panel assembly 1460′,rear wall panel assembly 1440′ and rear base panel assembly 1420′.Middle panel assembly 1300′ can include first middle enclosure panelassembly 1340′, middle wall and ceiling panel assembly 1360′ and secondmiddle enclosure panel assembly 1380′, as well as middle base panelassembly 1320′.

Additionally, middle panel assembly 1300′ can include first printheadmanagement system auxiliary panel assembly 1330′, as well as a secondprinthead management system auxiliary panel assembly (not shown). Aspreviously discussed herein, various embodiments of an auxiliaryenclosure constructed as a section of a gas enclosure assembly can besealably isolated from the working volume of a gas enclosure system.Such physical isolation of an auxiliary enclosure from, for example, aprinting system enclosure, can enable various procedures, for example,but not limited by, various maintenance procedures on a printheadassembly, to be conducted with little or no interruption of a printingprocess, thereby minimizing or eliminating gas enclosure systemdowntime.

As depicted in FIG. 10A, gas enclosure assembly 1000 can include frontbase panel assembly 1220′, middle base panel assembly 1320′, and rearbase panel assembly 1420′, which when fully-constructed form acontiguous base or pan on which OLED printing system 2000 can bemounted. In a similar fashion as described for gas enclosure assembly100 of FIG. 1A, the various frame members and panels comprising frontpanel assembly 1200′, middle panel assembly 1300′, and rear panelassembly 1400′ of gas enclosure assembly 1000 can be joined around OLEDprinting system 2000 to form a printing system enclosure. Accordingly, afully constructed gas enclosure assembly, such as gas enclosure assembly1000, when integrated with various environmental control systems canform various embodiments of a gas enclosure system including variousembodiments of OLED printing system 2000. According to variousembodiments of a gas enclosure system of the present teachings aspreviously described, environmental control of an interior volumedefined by a gas enclosure assembly can include control of lighting, forexample, by the number and placement of lights of a specific wavelength,control of particulate matter using various embodiments of a particlecontrol system, control of reactive gas species using variousembodiments of a gas purification system, and temperature control of agas enclosure assembly using various embodiments of a thermal controlsystem.

An OLED inkjet printing system, such as OLED printing system 2000 ofFIG. 10A, shown in expanded view in FIG. 10B, can be comprised ofseveral devices and apparatuses, which allow the reliable placement ofink drops onto specific locations on a substrate. These devices andapparatuses can include, but are not limited to, a printhead assembly,ink delivery system, a motion system for providing relative motionbetween a printhead assembly and a substrate, substrate supportapparatus, substrate loading and unloading system, and printheadmanagement system.

A printhead assembly can include at least one inkjet head, with at leastone orifice capable of ejecting droplets of ink at a controlled rate,velocity, and size. The inkjet head is fed by an ink supply system whichprovides ink to the inkjet head. As shown in an expanded view of FIG.10B, OLED inkjet printing system 2000 can have a substrate, such assubstrate 2050, which can be supported by a substrate support apparatus,such as a chuck, for example, but not limited by, a vacuum chuck, asubstrate floatation chuck having pressure ports, and a substratefloatation chuck having vacuum and pressure ports. In variousembodiments of systems and methods of the present teachings, a substratesupport apparatus can be a substrate floatation table. As will bediscussed in more detail subsequently herein, substrate floatation table2200 of FIG. 10B can be used for supporting substrate 2050, and inconjunction with a Y-axis motion system, can be part of a substrateconveyance system providing for the frictionless conveyance of substrate2050. A Y-axis motion system of the present teachings can include firstY-axis track 2351 and second Y-axis track 2352, which can include agripper system (not shown) for holding a substrate. Y-axis motion can beprovided by either a linear air bearing or linear mechanical system.Substrate floatation table 2200 of OLED inkjet printing system 2000shown in FIG. 10A and FIG. 10B can define the travel of substrate 2050through gas enclosure assembly 1000 of FIG. 9 during a printing process.

Printing requires relative motion between the printhead assembly and thesubstrate. This is accomplished with a motion system, typically a gantryor split axis XYZ system. Either the printhead assembly can move over astationary substrate (gantry style), or both the printhead and substratecan move, in the case of a split axis configuration. In anotherembodiment, a printhead assembly can be substantially stationary; forexample, in the X and Y axes, and the substrate can move in the X and Yaxes relative to the printheads, with Z axis motion provided either by asubstrate support apparatus or by a Z-axis motion system associated witha printhead assembly. As the printheads move relative to the substrate,droplets of ink are ejected at the correct time to be deposited in thedesired location on a substrate. A substrate can be inserted and removedfrom the printer using a substrate loading and unloading system.Depending on the printer configuration, this can be accomplished with amechanical conveyor, a substrate floatation table with a conveyanceassembly, or a substrate transfer robot with end effector. A printheadmanagement system can be comprised of several subsystems which allow forsuch measurement tasks, such as the checking for nozzle firing, as wellas the measurement of drop volume, velocity and trajectory from everynozzle in a printhead, and maintenance tasks, such as wiping or blottingthe inkjet nozzle surface of excess ink, priming and purging a printheadby ejecting ink from an ink supply through the printhead and into awaste basin, and replacement of printheads. Given the variety ofcomponents that can comprise an OLED printing system, variousembodiments of OLED printing system can have a variety of footprints andform factors.

With respect to FIG. 10B, printing system base 2100, can include firstriser (not visible) and second riser 2122, upon which bridge 2130 ismounted. For various embodiments of OLED printing system 2000, bridge2130 can support first X-axis carriage assembly 2301 and second X-axiscarriage assembly 2302, which can control the movement of firstprinthead assembly 2501 and second printhead assembly 2502, respectivelyacross bridge 2130. For various embodiments of printing system 2000,first X-axis carriage assembly 2301 and second X-axis carriage assembly2302 can utilize a linear air bearing motion system, which areintrinsically low-particle generating. According to various embodimentsof a printing system of the present teachings, an X-axis carriage canhave a Z-axis moving plate mounted thereupon. In FIG. 10B, first X-axiscarriage assembly 2301 is depicted with first Z-axis moving plate 2310,while second X-axis carriage assembly 2302 is depicted with secondZ-axis moving plate 2312. Though FIG. 10B depicts two carriageassemblies and two printhead assemblies, for various embodiments of OLEDinkjet printing system 2000, there can be a single carriage assembly anda single printhead assembly. For example, either of first printheadassembly 2501 and second printhead assembly 2502 can be mounted on anX,Z-axis carriage assembly, while a camera system for inspectingfeatures of substrate 2050 can be mounted on a second X,Z-axis carriageassembly. Various embodiments of OLED inkjet printing system 2000 canhave a single printhead assembly, for example, either of first printheadassembly 2501 and second printhead assembly 2502 can be mounted on anX,Z-axis carriage assembly, while a UV lamp for curing an encapsulationlayer printed on substrate 2050 can be mounted on a second X,Z-axiscarriage assembly. For various embodiments of OLED inkjet printingsystem 2000, there can be a single printhead assembly, for example,either of first printhead assembly 2501 and second printhead assembly2502, mounted on an X,Z-axis carriage assembly, while a heat source forcuring an encapsulation layer printed on substrate 2050 can be mountedon a second carriage assembly.

In FIG. 10B, first X,Z-axis carriage assembly 2301 can be used toposition first printhead assembly 2501, which can be mounted on firstZ-axis moving plate 2310, over substrate 2050, which is shown supportedon substrate floatation table 2200. Second X,Z-axis carriage assembly2302 with second Z-axis moving plate 2312 can be similarly configuredfor controlling the X-Z axis movement of second printhead assembly 2502relative to substrate 2050. Each printhead assembly, such as firstprinthead assembly 2501 and second printhead assembly 2502 of FIG. 10B,can have a plurality of printheads mounted in at least one printheaddevice, as depicted in partial view for first printhead assembly 2501,which depicts a plurality of printhead 2505. A printhead device caninclude, for example, but not limited by, fluidic and electronicconnections to at least one printhead; each printhead having a pluralityof nozzles or orifices capable of ejecting ink at a controlled rate,velocity and size. For various embodiments of printing system 2000, aprinthead assembly can include between about 1 to about 60 printheaddevices, where each printhead device can have between about 1 to about30 printheads in each printhead device. A printhead, for example, anindustrial inkjet head, can have between about 16 to about 2048 nozzles,which can expel a droplet volume of between about 0.1 pL to about 200pL.

According to various embodiments of a gas enclosure system of thepresent teachings, given the sheer number of printhead devices andprintheads, first printhead management system 2701 and second printheadmanagement system 2702 can be housed in an auxiliary enclosure, whichcan be isolated from a printing system enclosure during a printingprocess for performing various measurement and maintenance tasks withlittle or no interruption to the printing process. As can be seen inFIG. 10B, first printhead assembly 2501 can be seen positioned relativeto first printhead management system 2701 for ready performance ofvarious measurement and maintenance procedures that can be performed byfirst printhead management system apparatuses 2707, 2709 and 2711.Apparatuses 2707, 2709, and 2011 can be any of a variety of subsystemsor modules for performing various printhead management functions. Forexample apparatuses 2707, 2709, and 2011 can be any of a dropmeasurement module, a printhead replacement module, a purge basinmodule, and a blotter module.

FIG. 10C depicts an expanded view of first printhead management system2701 housed within first printhead management system auxiliary panelassembly 1330′ in accordance with various embodiments of a gas enclosureassembly and system of the present teachings. As depicted in FIG. 10C,auxiliary panel assembly 1330′ is shown as a cut-away view to moreclearly see the details of first printhead management system 2701.Various embodiments of a printhead management system according to thepresent teachings, such as first printhead management system 2701 ofFIG. 10C, apparatuses 2707, 2709, and 2011 can be a variety ofsubsystems or modules for performing various functions. For exampleapparatuses 2707, 2709, and 2011 can be a drop measurement module, aprinthead purge basin module and a blotter module. As depicted in FIG.10C, printhead replacement module 2713 can provide locations for dockingat least one printhead device 2505. In various embodiments of firstprinthead management system 2701, first printhead management systemauxiliary panel assembly 1330′ can be maintained to the sameenvironmental specifications that gas enclosure assembly 1000 (see FIG.19 ) is maintained. First printhead management system auxiliary panelassembly 1330′ can have handler 2530 positioned for the carrying outtasks associated with various printhead management procedures. Forexample, each subsystem can have various parts that are consumable bynature, and require replacement, such as replacing blotter paper, ink,and waste reservoirs. Various consumable parts can be packaged for readyinsertion, for example, in a fully automated mode using a handler. As anon-limiting example, blotter paper can be packaged in a cartridgeformat, which can be readily inserted for use into a blotting module. Byway of another non-limiting example ink can be packaged in a replaceablereservoir, as well as a cartridge format for use in a printing system.Various embodiments of a waste reservoir can be packaged in a cartridgeformat, which can be readily inserted for use into a purge basin module.Additionally, parts of various components of a printing system subjectto on-going use can require periodic replacement. During a printingprocess, expedient management of a printhead assembly, for example, butnot limited by, an exchange of a printhead device or printhead, can bedesirable. A printhead replacement module can have parts, such as aprinthead device or printhead, which can be readily inserted for useinto a printhead assembly. A drop measurement module used for checkingfor nozzle firing, as well as the measurement based on optical detectionof drop volume, velocity and trajectory from every nozzle can have asource and a detector, which can require periodic replacement after use.Various consumable and high-usage parts can be packaged for readyinsertion, for example, in a fully automated mode using a handler.Handler 2530 can have end effector 2536 mounted to arm 2534. Variousembodiments of an end effector configuration can be used, for example, ablade-type end effector, a clamp-type end effector, and a gripper-typeend effector. Various embodiments of an end effector can includemechanical grasping and clamping, as well as pneumatic orvacuum-assisted assemblies to either actuate portions of the endeffector or otherwise retain a printhead device or a printhead from aprinthead device.

Regarding the replacement of a printhead device or printhead, printheadreplacement module 2713 of printhead management system 2701 FIG. 10C caninclude a docking station for a printhead device having at least oneprinthead, as well as a storage receptacle for a printhead. As eachprinthead assembly (see FIG. 10B) can include between about 1 to about60 printhead devices, and as each printhead device can have betweenabout 1 to about 30 printheads, then various embodiments of a printingsystem of the present teachings can have between about 1 to about 1800printheads. In various embodiments of printhead replacement module 2713,while a printhead device is docked, each printhead mounted to theprinthead device can be maintained in an operable condition while not inuse in a printing system. For example, when placed in a docking station,each printhead on each printhead device can be connected to an inksupply and an electrical connection. Electrical power can be provided toeach printhead on each printhead device, so that a periodic firing pulseto each nozzle of each printhead can be applied while docked in order toensure that the nozzles remain primed and do not clog. Handler 2530 ofFIG. 10C can be positioned proximal to printhead assembly 2500.Printhead assembly 2500 can be docked over first printhead managementsystem auxiliary panel assembly 1330′, as depicted in FIG. 10C. During aprocedure for exchanging a printhead, handler 2530 can remove a targetpart; either a printhead or printhead device having at least oneprinthead, from printhead assembly 2500. Handler 2530 can retrieve areplacement part, such as a printhead device or a printhead, fromprinthead replacement module 2713, and complete the replacement process.The removed part can be placed in printhead replacement module 2713 forretrieval.

With respect to various embodiments of a gas enclosure assembly havingan auxiliary enclosure that can be closed off from, as well as sealablyisolated from a first working volume, for example, a printing systemenclosure, reference is made again to FIG. 10A. As depicted in FIG. 10B,there can be four isolators on OLED printing system 2000; first isolatorset 2110 (second not shown on opposing side) and second isolator set2112 (second not shown on opposing side), which support substratefloatation table 2200 of OLED printing system 2000. For gas enclosureassembly 1000 of FIG. 10A, first isolator set 2110 and second isolatorset 2112 can be mounted in each of a respective isolator well panel,such as first isolator wall panel 1325′ and second isolator wall panel1327′ of middle base panel assembly 1320′.For gas enclosure assembly1000 of FIG. 10A, middle base assembly 1320′ can include first printheadmanagement system auxiliary panel assembly 1330′, as well as secondprinthead management system auxiliary panel assembly 1370′. FIG. 10A ofgas enclosure assembly 1000 depicts first printhead management systemauxiliary panel assembly 1330′ that can include first back wall panelassembly 1338′. Similarly, also depicted is second printhead managementsystem auxiliary panel assembly 1370′ that can include second back wallpanel assembly 1378′. First back wall panel assembly 1338′ of firstprinthead management system auxiliary panel assembly 1330′ can beconstructed in a similar fashion as shown for second back wall panelassembly 1378′. Second back wall panel assembly 1378′ of secondprinthead management system auxiliary panel assembly 1370′ can beconstructed from second back wall frame assembly 1378 having secondseal-support panel 1375 sealably mounted to second back wall frameassembly 1378. Second seal-support panel 1375 can have second passage1365, which is proximal to a second end of base 2100 (not shown). Secondseal 1367 can be mounted on second seal-support panel 1375 around secondpassage 1365. A first seal can be similarly positioned and mountedaround a first passage for first printhead management system auxiliarypanel assembly 1330′. Each passage in auxiliary panel assembly 1330′ andauxiliary panel assembly 1370′ can accommodate having each maintenancesystem platform, such as first and second maintenance system platforms2703 and 2704 of FIG. 10B pass through the passages. As will bediscussed in more detail subsequently herein, in order to sealablyisolate auxiliary panel assembly 1330′ and auxiliary panel assembly1370′ the passages, such as second passage 1365 of FIG. 10A must besealable. It is contemplated that various seals, such as an inflatableseal, a bellows seal and a lip seal can be used for sealing a passage,such as second passage 1365 of FIG. 10A, around a maintenance platformaffixed to a printing system base.

First printhead management system auxiliary panel assembly 1330′ andsecond printhead management system auxiliary panel assembly 1370′ caninclude first printhead assembly opening 1342 of first floor panelassembly 1341′ and second printhead assembly opening 1382 of secondfloor panel assembly 1381′; respectively. First floor panel assembly1341′ is depicted in FIG. 10A as part of first middle enclosure panelassembly 1340′ of middle panel assembly 1300′. First floor panelassembly 1341′ is a panel assembly in common with both first middleenclosure panel assembly 1340′ and first printhead management systemauxiliary panel assembly 1330′. Second floor panel assembly 1381′ isdepicted in FIG. 10A as part of second middle enclosure panel assembly1380′ of middle panel assembly 1300′. Second floor panel assembly 1381′is a panel assembly in common with both second middle enclosure panelassembly 1380′ and second printhead management system auxiliary panelassembly 1370′.

As previously discussed herein, first printhead assembly 2501 can behoused in first printhead assembly enclosure 2503, and second printheadassembly 2502 can be housed in second printhead assembly enclosure 2504.According to systems and methods of the present teachings, firstprinthead assembly enclosure 2503 and second printhead assemblyenclosure 2504 can have an opening at the bottom that can have a rim(not shown), so that various printhead assemblies can be positioned forprinting during a printing process. Additionally, the portions of firstprinthead assembly enclosure 2503 and second printhead assemblyenclosure 2504 forming a housing can be constructed as previouslydescribed for various panel assemblies, so that the frame assemblymembers and panels are capable of providing an hermetically-sealedenclosure.

A compressible gasket, such as previously described for the hermeticsealing of various frame members, can be affixed around each of firstprinthead assembly opening 1342 and second printhead assembly opening1382, or alternatively around the rim of first printhead assemblyenclosure 2503 and second printhead assembly enclosure 2504.

As depicted in FIG. 10A, first printhead assembly docking gasket 1345and second printhead assembly docking gasket 1385 can be affixed aroundfirst printhead assembly opening 1342 and second printhead assemblyopening 1382, respectively. During various printhead measurement andmaintenance procedures, first printhead assembly 2501 and secondprinthead assembly 2502 can be positioned by first X,Z-axis carriageassembly 2301 and second X,Z-axis carriage assembly 2302, respectively,over first printhead assembly opening 1342 of first floor panel assembly1341′ and second printhead assembly opening 1382 of second floor panelassembly 1381′, respectively. In that regard, for various printheadmeasurement and maintenance procedures, first printhead assembly 2501and second printhead assembly 2502 can be positioned over firstprinthead assembly opening 1342 of first floor panel assembly 1341′ andsecond printhead assembly opening 1382 of second floor panel assembly1381′, respectively, without covering or sealing first printheadassembly opening 1342 and second printhead assembly opening 1382. FirstX,Z-axis carriage assembly 2301 and second X,Z-axis carriage assembly2302 can dock first printhead assembly enclosure 2503 and secondprinthead assembly enclosure 2504, respectively, with first printheadmanagement system auxiliary panel assembly 1330′ and second printheadmanagement system auxiliary panel assembly 1370′, respectively. Invarious printhead measurement and maintenance procedures, such dockingmay effectively close first printhead assembly opening 1342 and secondprinthead assembly opening 1382 without the need for sealing firstprinthead assembly opening 1342 and second printhead assembly opening1382. For various printhead measurement and maintenance procedures, thedocking can include the formation of a gasket seal between each of theprinthead assembly enclosures and the printhead management system panelassemblies. In conjunction with sealably closing passages, such assecond passage 1365 and a complementary first passage of FIG. 10A, whenfirst printhead assembly enclosure 2503 and second printhead assemblyenclosure 2504 are docked with first printhead management systemauxiliary panel assembly 1330′ and second printhead management systemauxiliary panel assembly 1370′ to sealably close first printheadassembly opening 1342 and second printhead assembly opening 1382, thecombined structures so formed are hermetically sealed.

Additionally, according to the present teachings, an auxiliary enclosurecan be isolated from, for example, another interior enclosure volume,such as the printing system enclosure, as well as the exterior of a gasenclosure assembly, by using a structural closure to sealably close apassageway, such as first printhead assembly opening 1342 and secondprinthead assembly opening 1382 of FIG. 10A. According to the presentteachings, a structural closure can include a variety of sealablecoverings for an opening or passageway; such opening or passagewayincluding non-limiting examples of an enclosure panel opening orpassageway. According to systems and methods of the present teachings, agate can be any structural closure that can be used to reversibly coveror reversibly sealably close any opening or passageway using pneumatic,hydraulic, electrical, or manual actuation. As such, first printheadassembly opening 1342 and second printhead assembly opening 1382 of FIG.10A can be reversibly covered or reversibly sealably closed using agate.

In the expanded view of OLED printing system 2000 of FIG. 10B, variousembodiments of a printing system can include substrate floatation table2200, supported by substrate floatation table base 2220. Substratefloatation table base 2220 can be mounted on printing system base 2100.Substrate floatation table 2200 of OLED printing system can supportsubstrate 2050, as well as defining the travel over which substrate 2050can be moved through gas enclosure assembly 1000 during the printing ofan OLED substrate. A Y-axis motion system of the present teachings caninclude first Y-axis track 2351 and second Y-axis track 2352, which caninclude a gripper system (not shown) for holding a substrate. Y-axismotion can be provided by either a linear air bearing or linearmechanical system. In that regard, in conjunction with a motion system;as depicted in FIG. 10B, a Y-axis motion system, substrate floatationtable 2200 can provide frictionless conveyance of substrate 2050 througha printing system.

FIG. 11 depicts a floatation table according to various embodiments ofthe present teachings for the frictionless support, and in conjunctionwith a conveyance system, the stable conveyance of a load, such assubstrate 2050 of FIG. 10B. Various embodiments of a floatation tablecan be used in any of the various embodiments of a gas enclosure systemof the present teachings. As previously discussed herein, variousembodiments of a gas enclosure system of the present teachings canprocess a range of sizes of OLED flat panel display substrates fromsmaller than a Gen 3.5 substrate, which has dimensions of about 61 cm×72cm, as well as the progression of larger generation sizes. It iscontemplated that various embodiments of gas enclosure system canprocess substrate sizes of Gen 5.5, having dimensions of about 130cm×150 cm, as well as a Gen 7.5 substrate, having dimensions of about195 cm×225 cm, and can be cut into eight 42″ or six 47″ flat panels persubstrate and larger. A Gen 8.5 substrate is approximately 220 cm×250cm, and can be cut to six 55″ or eight 46″ flat panels per substrate.However, substrate generation sizes keep advancing, so that acurrently-available Gen 10 substrate, having dimensions of about 285cm×305 cm, does not appear to be the ultimate generation of substratesizes. Additionally, sizes recited from the terminology arising from theuse of glass-based substrates can be applied to substrates of anymaterial suitable for use in OLED printing. For various embodiments ofan OLED inkjet printing system, a variety of substrate materials can beused for substrate 2050, for example, but not limited by, a variety ofglass substrate materials, as well as a variety of polymeric substratematerials. Accordingly, there are a variety of substrate sizes andmaterials requiring stable conveyance during printing in variousembodiments of gas enclosure systems of the present teachings.

As depicted if FIG. 11 , substrate floatation table 2200 according tovarious embodiments of the present teachings can have floatation tablebase 2220 for supporting a plurality of floatation table zones.Substrate floatation table 2200 can have zone 2210 in which bothpressure and vacuum can be applied through a plurality of ports. Such azone having both pressure and vacuum control can effectively provide afluidic spring between zone 2210 and a substrate (not shown). Zone 2210having both pressure and vacuum control is a fluidic spring withbidirectional stiffness. The gap that exits between a load and afloatation table surface is referred to as the fly height. A zone suchas zone 2210 of substrate floatation table 2200 of FIG. 11 , in which afluidic spring having bidirectional stiffness is created using aplurality of pressure and vacuum ports, can provide a controllable flyheight for a load, such as a substrate.

Proximal to zone 2210 are first and second transition zones; 2211 and2212, respectively, and then proximal first and second transition zones2211 and 2212 are pressure-only zones, 2213 and 2214, respectively. Inthe transition zones, the ratio of pressure to vacuum nozzles increasesgradually towards the pressure only zones to provide for a gradualtransition from zone 2210 to zones 2213 and 2214. For variousembodiments of a substrate floatation table, for example, as depicted inFIG. 11 , pressure-only zones 2213, 2214 are depicted as comprised ofrail structures. For various embodiments of a substrate floatationtable, pressure only zones, such as pressure-only zones 2213, 2214 ofFIG. 11 , can be comprised of a continuous plate, such as that depictedfor pressure-vacuum zone 2210 of FIG. 11 .

For various embodiments of a floatation table as depicted in FIG. 11 ,there can be essentially uniform height between the pressure-vacuumzone, the transition zone, and the pressure only zone, so that withintolerances, the three zones lie essentially in one plane and can vary inlength. For example, but not limited by, in order to provide a sense ofscale and proportion, for various embodiments of a floatation table ofthe present teachings, a transition zone can be about 400 mm, while thepressure-only zone can be about 2.5 m, and the pressure-vacuum zone canbe about 800 mm. In FIG. 11 , the pressure-only zones 2213 and 2214 donot provide a fluidic spring having bidirectional stiffness, andtherefore do not provide the control that zone 2210 can provide.Accordingly, the fly height of a load can be typically greater overpressure-only zones than the fly height of a substrate over apressure-vacuum zone, in order to allow enough height so that a loadwill not collide with a floatation table in the pressure-only zones. Forexample, but not limited by, it can be desirable for processing an OLEDpanel substrate to have a fly height of between about 150

to about 300

above pressure-only zones, such as zones 2213 and 2214, and then betweenabout 30

to about 50

above a pressure-vacuum zone, such as zone 2210.

Various embodiments of a gas enclosure system of the present teachingscan utilize a variety of devices, apparatuses and systems in addition agas circulation and filtration system for maintaining a controlled gasenclosure environment. For example, in addition to a gas circulation andfiltration system for providing a thorough and complete turnover of gasin the interior of a gas enclosure, a thermal regulation systemutilizing a plurality of heat exchangers can be provided to maintain adesired temperature in the interior of a gas enclosure. For example, aplurality of heat exchangers can be provided operating with, adjacentto, or used in conjunction with, a fan or another gas circulatingdevice. A gas purification loop can be configured to circulate gas fromwithin the interior of a gas enclosure assembly through at least one gaspurification component exterior the enclosure. In that regard, acirculation and filtration system internal a gas enclosure assembly inconjunction with a gas purification loop external a gas enclosureassembly can provide continuous circulation of a substantiallylow-particulate inert gas having substantially low levels of reactivespecies throughout a gas enclosure system. According to the presentteachings, an inert gas may be any gas that does not undergo a chemicalreaction under a defined set of conditions. Some commonly usednon-limiting examples of an inert gas can include nitrogen, any of thenoble gases, and any combination thereof. Various embodiments of a gasenclosure system having a gas purification system can be configured tomaintain very low levels of undesired components, for example, organicsolvents and vapors thereof, as well as water, water vapor, oxygen, andthe like. Such embodiments of a gas enclosure system can maintain levelsfor each species of various reactive species, including various reactiveatmospheric gases, such as water vapor and oxygen, as well as organicsolvent vapors at 100 ppm or lower, for example, at 10 ppm or lower, at1.0 ppm or lower, or at 0.1 ppm or lower.

FIG. 12 is a schematic diagram showing a gas enclosure system 501.Various embodiments of a gas enclosure system 501 according to thepresent teachings can comprise gas enclosure assembly 1101 for housing aprinting system, gas purification loop 3130 in fluid communication gasenclosure assembly 1101, and at least one thermal regulation system3140. Additionally, various embodiments of gas enclosure system 501 canhave pressurized inert gas recirculation system 3000, which can supplyinert gas for operating various devices, such as a substrate floatationtable for an OLED printing system. Various embodiments of a pressurizedinert gas recirculation system 3000 can utilize a compressor, a blowerand combinations of the two as sources for various embodiments ofpressurized inert gas recirculation system 3000, as will be discussed inmore detail subsequently herein. Additionally, gas enclosure system 501can have a circulation and filtration system internal to gas enclosuresystem 501 (not shown).

As depicted in FIG. 12 , for various embodiments of a gas enclosureassembly according to the present teachings, the design of the ductworkcan separate the inert gas circulated through gas purification loop 3130from the inert gas that is continuously filtered and circulatedinternally for various embodiments of a gas enclosure assembly. Gaspurification loop 3130 includes outlet line 3131 from gas enclosureassembly 1101, to a solvent removal component 3132 and then to gaspurification system 3134. Inert gas purified of solvent and otherreactive gas species, such as oxygen and water vapor, are then returnedto gas enclosure assembly 1101 through inlet line 3133. Gas purificationloop 3130 may also include appropriate conduits and connections, andsensors, for example, oxygen, water vapor and solvent vapor sensors. Agas circulating unit, such as a fan, blower or motor and the like, canbe separately provided or integrated, for example, in gas purificationsystem 3134, to circulate gas through gas purification loop 3130.According to various embodiments of a gas enclosure assembly, thoughsolvent removal system 3132 and gas purification system 3134 are shownas separate units in the schematic shown in FIG. 12 , solvent removalsystem 3132 and gas purification system 3134 can be housed together as asingle purification unit.

Gas purification loop 3130 of FIG. 12 can have solvent removal system3132 placed upstream of gas purification system 3134, so that inert gascirculated from gas enclosure assembly 1101 passes through solventremoval system 3132 via outlet line 3131. According to variousembodiments, solvent removal system 3132 may be a solvent trappingsystem based on adsorbing solvent vapor from an inert gas passingthrough solvent removal system 3132 of FIG. 12 . A bed or beds of asorbent, for example, but not limited by, such as activated charcoal,molecular sieves, and the like, may effectively remove a wide variety oforganic solvent vapors. For various embodiments of a gas enclosuresystem cold trap technology may be employed to remove solvent vapors insolvent removal system 3132. As previously discussed herein, for variousembodiments of a gas enclosure system according to the presentteachings, sensors, such as oxygen, water vapor and solvent vaporsensors, may be used to monitor the effective removal of such speciesfrom inert gas continuously circulating through a gas enclosure system,such as gas enclosure system 501 of FIG. 12 . Various embodiments of asolvent removal system can indicate when sorbent, such as activatedcarbon, molecular sieves, and the like, has reached capacity, so thatthe bed or beds of sorbent can be regenerated or replaced. Regenerationof a molecular sieve can involve heating the molecular sieve, contactingthe molecular sieve with a forming gas, a combination thereof, and thelike. Molecular sieves configured to trap various species, includingoxygen, water vapor, and solvents, can be regenerated by heating andexposure to a forming gas that comprises hydrogen, for example, aforming gas comprising about 96% nitrogen and 4% hydrogen, with saidpercentages being by volume or by weight. Physical regeneration ofactivated charcoal can be done using a similar procedure of heatingunder an inert environment.

Any suitable gas purification system can be used for gas purificationsystem 3134 of gas purification loop 3130 of FIG. 12 . Gas purificationsystems available, for example, from MBRAUN Inc., of Statham, N.H., orInnovative Technology of Amesbury, Mass., may be useful for integrationinto various embodiments of a gas enclosure assembly according to thepresent teachings. Gas purification system 3134 can be used to purifyone or more inert gases in gas enclosure system 501, for example, topurify the entire gas atmosphere within a gas enclosure assembly. Aspreviously discussed herein, in order to circulate gas through gaspurification loop 3130, gas purification system 3134 can have a gascirculating unit, such as a fan, blower or motor, and the like. In thatregard, a gas purification system can be selected depending on thevolume of the enclosure, which can define a volumetric flow rate formoving an inert gas through a gas purification system. For variousembodiments of gas enclosure system having a gas enclosure assembly witha volume of up to about 4 m3; a gas purification system that can moveabout 84 m³/h can be used. For various embodiments of gas enclosuresystem having a gas enclosure assembly with a volume of up to about 10m³; a gas purification system that can move about 155 m³/h can be used.For various embodiments of a gas enclosure assembly having a volume ofbetween about 52-114 m³, more than one gas purification system may beused.

Any suitable gas filters or purifying devices can be included in the gaspurification system 3134 of the present teachings. In some embodiments,a gas purification system can comprise two parallel purifying devices,such that one of the devices can be taken off line for maintenance andthe other device can be used to continue system operation withoutinterruption. In some embodiments, for example, the gas purificationsystem can comprise one or more molecular sieves. In some embodiments,the gas purification system can comprise at least a first molecularsieve, and a second molecular sieve, such that, when one of themolecular sieves becomes saturated with impurities, or otherwise isdeemed not to be operating efficiently enough, the system can switch tothe other molecular sieve while regenerating the saturated ornon-efficient molecular sieve. A control unit can be provided fordetermining the operational efficiency of each molecular sieve, forswitching between operation of different molecular sieves, forregenerating one or more molecular sieves, or for a combination thereof.As previously discussed herein, molecular sieves may be regenerated andreused.

Thermal regulation system 3140 of FIG. 12 can include at least onechiller 3142, which can have fluid outlet line 3141 for circulating acoolant into a gas enclosure assembly, and fluid inlet line 3143 forreturning the coolant to the chiller. An at least one fluid chiller 3142can be provided for cooling the gas atmosphere within gas enclosuresystem 501. For various embodiments of a gas enclosure system of thepresent teachings, fluid chiller 3142 delivers cooled fluid to heatexchangers within the enclosure, where inert gas is passed over afiltration system internal the enclosure. At least one fluid chiller canalso be provided with gas enclosure system 501 to cool heat evolvingfrom an apparatus enclosed within gas enclosure system 501. For example,but not limited by, at least one fluid chiller can also be provided forgas enclosure system 501 to cool heat evolving from an OLED printingsystem. Thermal regulation system 3140 can comprise heat-exchange orPeltier devices and can have various cooling capacities. For example,for various embodiments of a gas enclosure system, a chiller can providea cooling capacity of from between about 2 kW to about 20 kW. Variousembodiments of a gas enclosure system can have a plurality of fluidchillers that can chill one or more fluids. In some embodiments, thefluid chillers can utilize a number of fluids as coolant, for example,but not limited by, water, anti-freeze, a refrigerant, and a combinationthereof as a heat exchange fluid. Appropriate leak-free, lockingconnections can be used in connecting the associated conduits and systemcomponents.

As previously discussed herein, the present teachings disclose variousembodiments of a gas enclosure system that can include a printing systemenclosure defining a first volume and an auxiliary enclosure defining asecond volume. Various embodiments of a gas enclosure system can have anauxiliary enclosure that can be sealably constructed as a section of gasenclosure assembly. According to systems and methods of the presentteachings, an auxiliary enclosure can be sealable isolated from aprinting system enclosure, and can be opened to an environment externala gas enclosure assembly without exposing a printing system enclosure tothe external environment. Such physical isolation of an auxiliaryenclosure to perform, for example, but not limited by, various printheadmanagement procedures, can be done to eliminate or minimize the exposureof a printing system enclosure to contamination, such as air and watervapor and various organic vapors, as well as particulate contamination.Various printhead management procedures that can include measurement andmaintenance procedures on a printhead assembly can be done with littleor no interruption of a printing process, thereby minimizing oreliminating gas enclosure system downtime.

For various embodiments of systems and methods of the present teachings,an auxiliary enclosure can be less than or equal to about 1% of theenclosure volume of a gas enclosure system. In various embodiments ofsystems and methods of the present teachings, an auxiliary enclosure canbe can be less than or equal to about 2% of the enclosure volume of agas enclosure system. For various embodiments of systems and methods ofthe present teachings, an auxiliary enclosure can be less than or equalto about 5% of the enclosure volume of a gas enclosure system. Invarious embodiments of systems and methods of the present teachings, anauxiliary enclosure can be less than or equal to about 10% of theenclosure volume of a gas enclosure system. In various embodiments ofsystems and methods of the present teachings, an auxiliary enclosure canbe less than or equal to about 20% of the enclosure volume of a gasenclosure system. Should the opening of an auxiliary enclosure to anambient environment containing reactive gases be indicated forperforming, for example, a maintenance procedure, isolating an auxiliaryenclosure from the working volume of a gas enclosure can preventcontamination of the entire volume of a gas enclosure. Further, giventhe relatively small volume of an auxiliary enclosure in comparison tothe printing system enclosure portion of a gas enclosure, the recoverytime for an auxiliary enclosure can take significantly less time thanrecovery time for an entire printing system enclosure.

For a gas enclosure system having a printing system enclosure defining afirst volume and an auxiliary enclosure defining a second volume, bothvolumes can be readily integrated with gas circulation, filtration andpurification components to form a gas enclosure system that can sustainan inert, substantially low-particle environment for processes requiringsuch an environment with little or no interruption of a printingprocess. According to various systems and methods of the presentteachings, a printing system enclosure may be introduced to a level ofcontamination that is sufficiently low that a purification system canremove the contamination before it can affect a printing process.Various embodiments of an auxiliary enclosure can be a substantiallysmaller volume of the total volume of a gas enclosure assembly and canbe readily integrated with gas circulation, filtration and purificationcomponents to form an auxiliary enclosure system that can rapidlyrecover an inert, of a low-particle environment after exposure to anexternal environment, thereby providing little or no interruption of aprinting process.

According to systems and methods of the present teachings, variousembodiments of a printing system enclosure and an auxiliary enclosureconstructed as sections of a gas enclosure assembly can be constructedin a fashion to provide for separately-functioning frame member assemblysections. In addition to having all elements disclosed, by way ofnon-limiting examples, for gas enclosure systems 500 and 501, gasenclosure system 502 of FIG. 13 , can have first gas enclosure assemblysection 1101-S1 of gas enclosure assembly 1101 defining a first volumeand second gas enclosure assembly section 1101-S2 of gas enclosureassembly 1101 defining a second volume. If all valves, V₁, V₂, V₃ and V₄are opened, then gas purification loop 3130 operates essentially aspreviously described for gas enclosure assembly and system 1101 of FIG.12 . With closure of V₃ and V₄, only first gas enclosure assemblysection 1101-S1 is in fluid communication with gas purification loop3130. This valve state may be used, for example, but not limited by,when second gas enclosure assembly section 1101-S2 is sealably closedand thereby isolated from first gas enclosure assembly section 1101-S1during various measurement and maintenances procedure requiring thatsecond gas enclosure assembly section 1101-S2 be opened to theatmosphere. With closure of V₁ and V₂, only second gas enclosureassembly section 1101-S2 is in fluid communication with gas purificationloop 3130. This valve state may be used, for example, but not limitedby, during recovery of second gas enclosure assembly section 1101-S2after the section has been opened to the atmosphere. As previouslydiscussed herein for the present teachings related to FIG. 12 , therequirements for gas purification loop 3130 are specified with respectto the total volume of gas enclosure assembly 1101. Therefore, bydevoting the resources of a gas purification system to the recovery of agas enclosure assembly section, such as second gas enclosure assemblysection 1101-S2, which is depicted for gas enclosure system 502 of FIG.13 to be significantly less in volume than the total volume of gasenclosure 1101, the recovery time can be substantially reduced.

Additionally, various embodiments of an auxiliary enclosure can bereadily integrated with a dedicated set of environmental regulationsystem components, such as lighting, gas circulation and filtration, gaspurification, and thermostating components. In that regard, variousembodiments of a gas enclosure system that include an auxiliaryenclosure that can be sealably isolated as a section of gas enclosureassembly can have a controlled environment that is set to be uniformwith a first volume defined by a gas enclosure assembly housing aprinting system. Further, various embodiments of a gas enclosure systemincluding an auxiliary enclosure that can be sealably isolated as asection of gas enclosure assembly can have a controlled environment thatis set to be different than the controlled environment of a first volumedefined by a gas enclosure assembly housing a printing system.

Recalling, various embodiments of a gas enclosure assembly utilized inembodiments of a gas enclosure system of the present teachings can beconstructed in a contoured fashion that minimizes the internal volume ofa gas enclosure assembly, and at the same time optimizes the workingvolume for accommodating various footprints of OLED printing systemsdesigns. For example, various embodiments of a contoured gas enclosureassembly according to the present teachings can have a gas enclosurevolume of between about 6 m³ to about 95 m³ for various embodiments of agas enclosure assembly of the present teachings covering, for example,substrate sizes from Gen 3.5 to Gen 10. Various embodiments of acontoured gas enclosure assembly according to the present teachings canhave a gas enclosure volume of, for example, but not limited by, ofbetween about 15 m³ to about 30 m³, which might be useful for OLEDprinting of, for example, Gen 5.5 to Gen 8.5 substrate sizes. Variousembodiments of an auxiliary enclosure can be constructed as a section ofgas enclosure assembly and readily integrated with gas circulation andfiltration, as well as purification components to form a gas enclosuresystem that can sustain an inert, substantially low-particle environmentfor processes requiring such an environment.

As shown in FIG. 12 and FIG. 13 , various embodiments of a gas enclosuresystem can include a pressurized inert gas recirculation system 3000.Various embodiments of a pressurized inert gas recirculation loop canutilize a compressor, a blower and combinations thereof.

For example, as shown in FIG. 14 and FIG. 15 , various embodiments ofgas enclosure system 503 and gas enclosure system 504 can have externalgas loop 3200 for integrating and controlling inert gas source 3201 andclean dry air (CDA) source 3203 for use in various aspects of operationof gas enclosure system 503 and gas enclosure system 504. Gas enclosuresystem 503 and gas enclosure system 504 can also include variousembodiments of an internal particle filtration and gas circulationsystem, as well as various embodiments of an external gas purificationsystem, as previously described. Such embodiments of a gas enclosuresystem can include a gas purification system for purifying variousreactive species from an inert gas. Some commonly used non-limitingexamples of an inert gas can include nitrogen, any of the noble gases,and any combination thereof. Various embodiments of a gas purificationsystem according to the present teachings can maintain levels for eachspecies of various reactive species, including various reactiveatmospheric gases, such as water vapor and oxygen, as well as organicsolvent vapors at 100 ppm or lower, for example, at 10 ppm or lower, at1.0 ppm or lower, or at 0.1 ppm or lower. In addition to external loop3200 for integrating and controlling inert gas source 3201 and CDAsource 3203, gas enclosure system 503 and gas enclosure system 504 canhave compressor loop 3250, which can supply inert gas for operatingvarious devices and apparatuses that can be disposed in the interior ofgas enclosure system 503 and gas enclosure system 504.

Compressor loop 3250 of FIG. 14 can include compressor 3262, firstaccumulator 3264 and second accumulator 3268, which are configured to bein fluid communication. Compressor 3262 can be configured to compressinert gas withdrawn from gas enclosure assembly 1101 to a desiredpressure. An inlet side of compressor loop 3250 can be in fluidcommunication with gas enclosure assembly 1101 via gas enclosureassembly outlet 3252 through line 3254, having valve 3256 and checkvalve 3258. Compressor loop 3250 can be in fluid communication with gasenclosure assembly 1101 on an outlet side of compressor loop 3250 viaexternal gas loop 3200. Accumulator 3264 can be disposed betweencompressor 3262 and the junction of compressor loop 3250 with externalgas loop 3200 and can be configured to generate a pressure of 5 psig orhigher. Second accumulator 3268 can be in compressor loop 3250 forproviding dampening fluctuations due to compressor piston cycling atabout 60 Hz. For various embodiments of compressor loop 3250, firstaccumulator 3264 can have a capacity of between about 80 gallons toabout 160 gallons, while second accumulator can have a capacity ofbetween about 30 gallons to about 60 gallons. According to variousembodiments of gas enclosure system 503, compressor 3262 can be a zeroingress compressor. Various types of zero ingress compressors canoperate without leaking atmospheric gases into various embodiments of agas enclosure system of the present teachings. Various embodiments of azero ingress compressor can be run continuously, for example, during anOLED printing process utilizing the use of various devices andapparatuses requiring compressed inert gas.

Accumulator 3264 can be configured to receive and accumulate compressedinert gas from compressor 3262. Accumulator 3264 can supply thecompressed inert gas as needed in gas enclosure assembly 1101. Forexample, accumulator 3264 can provide gas to maintain pressure forvarious components of gas enclosure assembly 1101, such as, but notlimited by, one or more of a pneumatic robot, a substrate floatationtable, an air bearing, an air bushing, a compressed gas tool, apneumatic actuator, and combinations thereof. As shown in FIG. 14 forgas enclosure system 503, gas enclosure assembly 1101 can have an OLEDprinting system 2000 enclosed therein. As schematically depicted in FIG.14 , inkjet printing system 2000 can be supported by printing systembase 2100, which can be a granite stage. Printing system base 2100 cansupport a substrate support apparatus, such as a chuck, for example, butnot limited by, a vacuum chuck, a substrate floatation chuck havingpressure ports, and a substrate floatation chuck having vacuum andpressure ports. In various embodiments of the present teachings, asubstrate support apparatus can be a substrate floatation table, such assubstrate floatation table 2200 indicated in FIG. 14 . Substratefloatation table 2200 can be used for the frictionless support of asubstrate. In addition to a low-particle generating floatation table,for frictionless Y-axis conveyance of a substrate, printing system 2000can have a Y-axis motion system utilizing air bushings. Additionally,printing system 2000 can have at least one X,Z-axis carriage assemblywith motion control provided by a low-particle generating X-axis airbearing assembly. Various components of a low-particle generating motionsystem, such as an X-axis air bearing assembly, can be used in place of,for example, various particle-generating linear mechanical bearingsystems. For various embodiments of a gas enclosure and system of thepresent teachings, the use of a variety of pneumatically operateddevices and apparatuses can provide low-particle generating performance,as well as being low maintenance. Compressor loop 3250 can be configuredto continuously supply pressurized inert gas to various devices andapparatuses of gas enclosure system 503. In addition to a supply ofpressurized inert gas, substrate floatation table 2200 of inkjetprinting system 2000, which utilizes air bearing technology, alsoutilizes vacuum system 3270, which is in communication with gasenclosure assembly 1101 through line 3272 when valve 3274 is in an openposition.

A pressurized inert gas recirculation system according to the presentteachings can have pressure-controlled bypass loop 3260 as shown in FIG.14 for compressor loop 3250, which acts to compensate for variabledemand of pressurized gas during use, thereby providing dynamic balancefor various embodiments of a gas enclosure system of the presentteachings. For various embodiments of a gas enclosure system accordingto the present teachings, a bypass loop can maintain a constant pressurein accumulator 3264 without disrupting or changing the pressure inenclosure 1101. Bypass loop 3260 can have first bypass inlet valve 3261on an inlet side of bypass loop, which is closed unless bypass loop 3260is used. Bypass loop 3260 can also have back pressure regulator 3266,which can be used when second valve 3263 is closed. Bypass loop 3260 canhave second accumulator 3268 disposed at an outlet side of bypass loop3260. For embodiments of compressor loop 3250 utilizing a zero ingresscompressor, bypass loop 3260 can compensate for small excursions ofpressure that can occur over time during use of a gas enclosure system.Bypass loop 3260 can be in fluid communication with compressor loop 3250on an inlet side of bypass loop 3260 when bypass inlet valve 3261 is inan opened position. When bypass inlet valve 3261 is opened, inert gasshunted through bypass loop 3260 can be recirculated to the compressorif inert gas from compressor loop 3250 is not in demand within theinterior of gas enclosure assembly 1101. Compressor loop 3250 isconfigured to shunt inert gas through bypass loop 3260 when a pressureof the inert gas in accumulator 3264 exceeds a pre-set thresholdpressure. A pre-set threshold pressure for accumulator 3264 can be frombetween about 25 psig to about 200 psig at a flow rate of at least about1 cubic feet per minute (cfm), or from between about 50 psig to about150 psig at a flow rate of at least about 1 cubic feet per minute (cfm),or from between about 75 psig to about 125 psig at a flow rate of atleast about 1 cubic feet per minute (cfm) or between about 90psig toabout 95psig at a flow rate of at least about 1 cubic feet per minute(cfm).

Various embodiments of compressor loop 3250 can utilize a variety ofcompressors other than a zero ingress compressor, such as a variablespeed compressor or a compressor that can be controlled to be in eitheran on or off state. As previously discussed herein, a zero ingresscompressor ensures that no atmospheric reactive species can beintroduced into a gas enclosure system. As such, any compressorconfiguration preventing atmospheric reactive species from beingintroduced into a gas enclosure system can be utilized for compressorloop 3250. According to various embodiments, compressor 3262 of gasenclosure system 503can be housed in, for example, but not limited by,an hermetically-sealed housing. The housing interior can be configuredin fluid communication with a source of inert gas, for example, the sameinert gas that forms the inert gas atmosphere for gas enclosure assembly1101. For various embodiments of compressor loop 3250, compressor 3262can be controlled at a constant speed to maintain a constant pressure.In other embodiments of compressor loop 3250 not utilizing a zeroingress compressor, compressor 3262 can be turned off when a maximumthreshold pressure is reached, and turned on when a minimum thresholdpressure is reached.

In FIG. 15 for gas enclosure system 504, blower loop 3280 utilizingvacuum blower 3290 is shown for the operation of substrate floatationtable 2200 of inkjet printing system 2000, which are housed in gasenclosure assembly 1101. As previously discussed herein for compressorloop 3250, blower loop 3280 can be configured to continuously supplypressurized inert gas to a substrate floatation table 2200 of printingsystem 2000.

Various embodiments of a gas enclosure system that can utilize apressurized inert gas recirculation system can have various loopsutilizing a variety of pressurized gas sources, such as at least one ofa compressor, a blower, and combinations thereof. In FIG. 15 for gasenclosure system 504, compressor loop 3250 can be in fluid communicationwith external gas loop 3200, which can be used for the supply of inertgas for high consumption manifold 3225, as well as low consumptionmanifold 3215. For various embodiments of a gas enclosure systemaccording to the present teachings as shown in FIG. 15 for gas enclosuresystem 504, high consumption manifold 3225 can be used to supply inertgas to various devices and apparatuses, such as, but not limited by, oneor more of a substrate floatation table, a pneumatic robot, an airbearing, an air bushing, and a compressed gas tool, and combinationsthereof. For various embodiments of a gas enclosure system according tothe present teachings, low consumption 3215 can be used to supply inertgas to various apparatuses and devises, such as, but not limited by, oneor more of an isolator, and a pneumatic actuator, and combinationsthereof.

For various embodiments of gas enclosure system 504 of FIG. 15 , blowerloop 3280 can be utilized to supply pressurized inert gas to variousembodiments of substrate floatation table 2200, while compressor loop3250; in fluid communication with external gas loop 3200, can beutilized to supply pressurized inert gas to, for example, but notlimited by, one or more of a pneumatic robot, an air bearing, an airbushing, and a compressed gas tool, and combinations thereof. Inaddition to a supply of pressurized inert gas, substrate floatationtable 2200 of OLED inkjet printing system 2000, which utilizes airbearing technology, also utilizes blower vacuum 3290, which is incommunication with gas enclosure assembly 1101 through line 3292 whenvalve 3294 is in an open position. Housing 3282 of blower loop 3280 canmaintain first blower 3284 for supplying a pressurized source of inertgas to substrate floatation table 2200, and second blower 3290, actingas a vacuum source for substrate floatation table 2200, which is housedin an inert gas environment in gas enclosure assembly 1101. Attributesthat can make blowers suitable for use as a source of either pressurizedinert gas or vacuum for various embodiments a substrate floatation tableinclude, for example, but not limited by, that they have highreliability; making them low maintenance, have variable speed control,and have a wide range of flow volumes; various embodiments capable ofproviding a volume flow of between about 100 m³/h to about 2,500 m³/h.Various embodiments of blower loop 3280 additionally can have firstisolation valve 3283 at an inlet end of blower loop 3280, as well ascheck valve 3285 and a second isolation valve 3287 at an outlet end ofblower loop 3280. Various embodiments of blower loop 3280 can haveadjustable valve 3286, which can be, for example, but not limited by, agate, butterfly, needle or ball valve, as well as heat exchanger 3288for maintaining inert gas from blower loop 3280 to substrate floatationtable 2200 at a defined temperature.

FIG. 15 depicts external gas loop 3200, also shown in FIG. 14 , forintegrating and controlling inert gas source 3201 and clean dry air(CDA) source 3203 for use in various aspects of operation of gasenclosure system 503 of FIG. 14 and gas enclosure system 504 of FIG. 15. External gas loop 3200 of FIG. 14 and FIG. 15 can include at leastfour mechanical valves. These valves comprise first mechanical valve3202, second mechanical valve 3204, third mechanical valve 3206, andfourth mechanical valve 3208. These various valves are located atpositions in various flow lines that allow control of both an inert gasand an air source such as clean dry air (CDA). According to the presentteachings, an inert gas may be any gas that does not undergo a chemicalreaction under a defined set of conditions. Some commonly usednon-limiting examples of an inert gas can include nitrogen, any of thenoble gases, and any combination thereof. From a house inert gas source3201, a house inert gas line 3210 extends. House inert gas line 3210continues to extend linearly as low consumption manifold line 3212,which is in fluid communication with low consumption manifold 3215. Across-line first section 3214 extends from a first flow juncture 3216,which is located at the intersection of house inert gas line 3210, lowconsumption manifold line 3212, and cross-line first section 3214.Cross-line first section 3214 extends to a second flow juncture 3218. Acompressor inert gas line 3220 extends from accumulator 3264 ofcompressor loop 3250 and terminates at second flow juncture 3218. A CDAline 3222 extends from a CDA source 3203 and continues as highconsumption manifold line 3224, which is in fluid communication withhigh consumption manifold 3225. A third flow juncture 3226 is positionedat the intersection of a cross-line second section 3228, clean dry airline 3222, and high consumption manifold line 3224. Cross-line secondsection 3228 extends from second flow juncture 3218 to third flowjuncture 3226. Various components that are high consumption can besupplied CDA during maintenance, by means high consumption manifold3225. Isolating the compressor using valves 3204, 3208, and 3230 canprevent reactive species, such as oxygen and water vapor fromcontaminating an inert gas within the compressor and accumulator.

The continual circulation and filtration of inert gas variousembodiments of a gas enclosure assembly are a part of a particle controlsystem that can provide for maintaining a substantially low-particleenvironment within various embodiments of a gas enclosure system.Various embodiments of a gas circulation and filtration system can bedesigned to provide a low particle environment for airborne particulatesmeeting the standards of International Standards Organization Standard(ISO) 14644-1:1999, “Cleanrooms and associated controlledenvironments—Part 1: Classification of air cleanliness,” as specified byClass 1 through Class 5. Additionally, various components of a particlecontrol system can exhaust particulate matter into a gas circulation andfiltration system in order to maintain a low-particle zone proximal to asubstrate. A determination of airborne particulate matter can beperformed for various embodiments of a gas enclosure system before aprinting process for system validation, using, for example, a portableparticle counting device. In various embodiments of a gas enclosuresystem, a determination of airborne particulate matter can be performedas an ongoing quality check in situ while a substrate is printed. Forvarious embodiments of a gas enclosure system, a determination ofairborne particulate matter can be performed for system validationbefore a substrate is printed and additionally in situ while a substrateis printed.

Various embodiments of a gas circulation and filtration system aredepicted in FIG. 16 through FIG. 18 . According to various embodimentsof a gas circulation and filtration system of the present teachings,ductwork can be installed in an interior portion formed by the joiningof wall frame and ceiling frame members. For various embodiments of agas enclosure assembly, ductwork may be installed during theconstruction process. According to various embodiments of the presentteachings, ductwork may be installed within a gas enclosure frameassembly, which has been constructed from a plurality of frame members.In various embodiments, ductwork can be installed on a plurality offrame members before they are joined to form a gas enclosure frameassembly. Ductwork for various embodiments of a gas enclosure system canbe configured such that substantially all gas drawn into the ductworkfrom one or more ductwork inlets is moved through various embodiments ofa gas filtration loop for removing particulate matter internal a gasenclosure assembly. Additionally, ductwork of various embodiments of agas enclosure system can be configured to separate the inlets andoutlets of a gas purification loop external to a gas enclosure assemblyfrom the gas filtration loop for removing particulate matter internal toa gas enclosure assembly. Various embodiments of ductwork in accordancewith the present teachings can be fabricated from metal sheet, forexample, but not limited by, aluminum sheet having a thickness of about80 mil.

FIG. 16 depicts a right front phantom perspective view of circulationand filtration system 1500, which can include ductwork assembly 1501 andfan filter unit assembly 1502 of gas enclosure assembly 100. Enclosureductwork assembly 1501 can have front wall panel ductwork assembly 1510.As shown front wall panel ductwork assembly 1510 can have front wallpanel inlet duct 1512, first front wall panel riser 1514 and secondfront wall panel riser 1516, both of which are in fluid communicationwith front wall panel inlet duct 1512. First front wall panel riser 1514is shown having outlet 1515, which is sealably engaged with ceiling duct1505 of fan filter unit cover 103. In a similar fashion, second frontwall panel riser 1516 is shown having outlet 1517, which is sealablyengaged with ceiling duct 1507 of fan filter unit cover 103. In thatregard, front wall panel ductwork assembly 1510 provides for circulatinginert gas within a gas enclosure system from the bottom, utilizing frontwall panel inlet duct 1512, through each front wall panel riser, 1514and 1516, and delivering the air through outlets 1505 and 1507,respectively, so that the air can be filtered by, for example, fanfilter unit 1552 of fan filter unit assembly 1502. Proximal fan filterunit 1552 is heat exchanger 1562, which as part of a thermal regulationsystem, can maintain inert gas circulating through gas enclosureassembly 100 at a desired temperature.

Right wall panel ductwork assembly 1530 can have right wall panel inletduct 1532, which is in fluid communication with right wall panel upperduct 1538 through right wall panel first riser 1534 and right wall panelsecond riser 1536. Right wall panel upper duct 1538, can have first ductinlet end 1535 and second duct outlet end 1537, which second duct outletend 1537 is in fluid communication with rear wall panel upper duct 1546of rear wall ductwork assembly 1540. Left wall panel ductwork assembly1520 can have the same components as described for right wall panelassembly 1530, of which left wall panel inlet duct 1522, which is influid communication with left wall panel upper duct (not shown) throughfirst left wall panel riser 1524 and first left wall panel riser 1524are apparent in FIG. 16 . Rear wall panel ductwork assembly 1540 canhave rear wall panel inlet duct 1542, which is in fluid communicationwith left wall panel assembly 1520 and right wall panel assembly 1530.Additionally, rear wall panel ductwork assembly 1540, can have rear wallpanel bottom duct 1544, which can have rear wall panel first inlet 1541and rear wall panel second inlet 1543. Rear wall panel bottom duct 1544can be in fluid communication with rear wall panel upper duct 1546 viafirst bulkhead 1547 and second bulkhead 1549, which bulkhead structurescan be used to feed, for example, but not limited by, a service from theexterior of gas enclosure assembly 100 into the interior. According tothe present teachings, a service bundle can include, for example, butnot limited by, optical cables, electrical cables, wires and tubing, andthe like. Recalling, a manufacturing facility can require a substantiallength of various service bundles that can be operatively connected fromvarious systems and assemblies to provide optical, electrical,mechanical, and fluidic connections required to operate a printingsystem. Duct opening 1533 provides for moving at least one servicebundle out of rear wall panel upper duct 1546, which can be passedthrough rear wall panel upper duct 1546 via bulkhead 1549. Bulkhead 1547and bulkhead 1549 can be hermetically sealed on the exterior using aremovable inset panel, as previously described. Rear wall panel upperduct is in fluid communication with, for example, but not limited by,fan filter unit 1554 through vent 545, of which a corner is shown inFIG. 16 . In that regard, left wall panel ductwork assembly 1520, rightwall panel ductwork assembly 1530, and rear wall panel ductwork assembly1540 provide for circulating inert gas within a gas enclosure assemblyfrom the bottom, utilizing wall panel inlet ducts 1522, 1532, and 1542,respectively, as well as rear panel lower duct 1544, which are in fluidcommunication with vent 1545 through various risers, ducts, bulkheadpassages, and the like as previously described. Accordingly, air can befiltered by, for example, fan filter unit 1554 of fan filter unitassembly 1502 of circulation and filtration system 1500. Proximal fanfilter unit 1554 is heat exchanger 1564, which as part of a thermalregulation system, can maintain inert gas circulating through gasenclosure assembly 100 at a desired temperature. As will be discussed inmore detail subsequently herein, the number, size and shape of fanfilter units for a fan filter unit assembly, such as fan filter unitassembly 1502 including fan filter unit 1552 and 1554 of circulation andfiltration system 1500, can be selected in accordance with the physicalposition of a substrate in a printing system during processing. Thenumber, size and shape of fan filter units for a fan filter unitassembly selected with respect to the physical travel of a substrate canbe an element of a low-particle gas enclosure system, which can providea low-particle zone proximal a substrate during a substratemanufacturing process.

In FIG. 16 , cable feed through opening 1533 is shown. As will bediscussed in more detail subsequently herein, various embodiments of agas enclosure assembly of the present teachings provide for bringing aservice bundle through ductwork. In order to eliminate leak paths formedaround such service bundles, various approaches for sealing differentlysized cables, wires, and tubings in a service bundle using conformingmaterial can be used. Also shown in FIG. 16 for enclosure ductworkassembly 1501 is conduit I and conduit II, which are shown as part offan filter unit cover 103. Conduit I provides an outlet of inert gas toan external gas purification system, while conduit II provides a returnof purified inert gas to the circulation and filtration loop internalgas enclosure assembly 100.

In FIG. 17 , a top phantom perspective view of enclosure ductworkassembly 1501 is shown. The symmetric nature of left wall panel ductworkassembly 1520 and right wall panel ductwork assembly 1530 can be seen.For right wall panel ductwork assembly 1530, right wall panel inlet duct1532, is in fluid communication with right wall panel upper duct 1538through right wall panel first riser 1534 and right wall panel secondriser 1536. Right wall panel upper duct 1538, can have first duct inletend 1535 and second duct outlet end 1537, which second duct outlet end1537 is in fluid communication with rear wall panel upper duct 1546 ofrear wall ductwork assembly 1540. Similarly, left wall panel ductworkassembly 1520 can have left wall panel inlet duct 1522, which is influid communication with left wall panel upper duct 1528 through leftwall panel first riser 1524 and left wall panel second riser 1526. Leftwall panel upper duct 1528, can have first duct inlet end 1525 andsecond duct outlet end 1527, which second duct outlet end 1527 is influid communication with rear wall panel upper duct 1546 of rear wallductwork assembly 1540. Additionally, rear wall panel ductwork assemblycan have rear wall panel inlet duct 1542, which is in fluidcommunication with left wall panel assembly 1520 and right wall panelassembly 1530. Additionally, rear wall panel ductwork assembly 1540, canhave rear wall panel bottom duct 1544, which can have rear wall panelfirst inlet 1541 and rear wall panel second inlet 1543. Rear wall panelbottom duct 1544 can be in fluid communication with rear wall panelupper duct 1546 via first bulkhead 1547 and second bulkhead 1549.Ductwork assembly 1501 as shown in FIG. 16 and FIG. 17 can provideeffective circulation of inert gas from front wall panel ductworkassembly 1510, which circulates inert gas from front wall panel inletduct 1512 to ceiling panel ducts 1505 and 1507 via front wall paneloutlets 1515 and 1517, respectively, as well as from left wall panelassembly 1520, right wall panel assembly 1530 and rear wall panelductwork assembly 1540, which circulate air from inlet ducts 1522, 1532,and 1542, respectively to vent 1545. Once inert gas is exhausted viaceiling panel ducts 1505 and 1507 and vent 1545 into the enclosure areaunder fan filter unit cover 103 of enclosure 100, the inert gas soexhausted can be filtered through fan filter units 1552 and 1554 of fanfilter unit assembly 1502. Additionally, the circulated inert gas can bemaintained at a desired temperature by heat exchangers 1562 and 1564,which are part of a thermal regulation system.

FIG. 18 is a bottom phantom view of enclosure ductwork assembly 1501.Inlet ductwork assembly 1509 includes front wall panel inlet duct 1512,left wall panel inlet duct 1522, right wall panel inlet duct 1532, andrear wall panel inlet duct 1542, which are in fluid communication withone another. As previously discussed herein, conduit I provides anoutlet of inert gas to an external gas purification system, whileconduit II provides a return of purified inert gas to the circulationand filtration loop internal to gas enclosure assembly 100.

For each inlet duct included in inlet ductwork assembly 1509, there areapparent openings evenly distributed across the bottom of each duct,sets of which are specifically highlighted for the purpose of thepresent teachings, as openings 1511 of front wall panel inlet duct 1512,openings 1521 of left wall panel inlet duct 1522, openings 1531 of rightwall panel inlet duct 1532, and openings 1541 of right wall panel inletduct 1542. Such openings, as are apparent across the bottom of eachinlet duct, provide for effective uptake of inert gas within enclosure100 for continual circulation and filtration. The continual circulationand filtration of inert gas various embodiments of a gas enclosureassembly are a part of a particle control system that can provide formaintaining a substantially low-particle environment within variousembodiments of a gas enclosure system. Various embodiments of a gascirculation and filtration system can be designed to provide a lowparticle environment for maintaining airborne particulate levels meetingthe standards of International Standards Organization Standard (ISO)14644-1:1999, as specified by Class 1 through Class 5. Additionally, aservice bundle that can include cables, wires, and tubings and the like,bundled together, can act as a source of particulate matter.Accordingly, having service bundles fed through ductwork can contain anidentified source of particles within the ductwork and exhaust theparticulate matter through a circulation and filtration system.

Various embodiments of a gas enclosure system can have a particlecontrol system that can maintain a substantially low-particleenvironment providing for an on-substrate particle specification forparticles of between about 0.1 □m or greater to about 10 □m or greater.Various embodiments of an on-substrate particle specification can bereadily converted from an average on-substrate particle distribution persquare meter of substrate per minute to an average on-substrate particledistribution per substrate per minute for each of a target particle sizerange. As previously discussed herein, such a conversion can be readilydone through a known relationship between substrates, for example, of aspecific generation-sized substrate and the corresponding area for thatsubstrate generation. Additionally, an average on-substrate particledistribution per square meter of substrate per minute can be readilyconverted to any of a variety of unit time expressions. For example, inaddition to conversions between standard units of time; e.g. seconds,minutes, and days, units of time specifically relating to processing canbe used. For example, as previously discussed herein, a print cycle canbe associated with a unit of time.

Various embodiments of a low-particle gas enclosure system of thepresent teachings can maintain a low-particle environment providing foran average on-substrate particle distribution that meets an on-substratedeposition rate specification of less than or equal to about 100particles per square meter of substrate per minute for particles greaterthan or equal to 10

m in size. Various embodiments of a low-particle gas enclosure system ofthe present teachings can maintain a low-particle environment providingfor an average on-substrate particle distribution that meets anon-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 5

m in size. In various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 2

m in size. In various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 1

m in size. Various embodiments of a low-particle gas enclosure system ofthe present teachings can maintain a low-particle environment providingfor an average on-substrate particle distribution that meets anon-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.5

m in size. For various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.3

m in size. Various embodiments of a low-particle gas enclosure system ofthe present teachings can maintain a low-particle environment providingfor an average on-substrate particle distribution that meets anon-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.1

m in size.

A manufacturing facility can require a substantial length of variousservice bundles that can be operatively connected from variousapparatuses and systems to provide optical, electrical, mechanical, andfluidic connections required, for example, to operate a printing system.According to the present teachings, a service bundle can include, forexample, but not limited by, optical cables, electrical cables, wiresand tubing, and the like. Various embodiments of a service bundleaccording to the present teachings can have a significant total deadvolume as a result of a substantial number of void spaces created bybundling various cables, wires and tubing, and the like together in aservice bundle. The total dead volume resulting from a substantialnumber of void spaces in a service bundle can result in the retention ofa significant volume of reactive gaseous species occluded therein. Sucha substantial source of reactive atmospheric gases can significantlyincrease recovery time of a gas enclosure assembly, for example, aftermaintenance.

Accordingly, in addition to providing a component of a particle controlsystem, feeding a service bundle through ductwork can reduce therecovery time of a gas enclosure assembly with respect to reactivespecies; thereby more rapidly bringing a gas enclosure assembly backwithin the specifications for performing an air-sensitive process. Forvarious embodiments of a gas enclosure system of the present teachingsuseful for printing OLED devices, each species of various reactivespecies, including various reactive atmospheric gases, such as watervapor and oxygen, as well as organic solvent vapors can be maintained at100 ppm or lower, for example, at 10 ppm or lower, at 1.0 ppm or lower,or at 0.1 ppm or lower.

To understand how cabling fed through ductwork can result in decreasingthe time it takes to purge occluded reactive atmospheric gases from deadvolumes created by void spaces in a service bundle, which are created asa result of bundling various optical cables, electrical cables, wiresand fluidic tubing, and the like, reference is made to FIGS. 19A, 19Band 20 . FIG. 19A depicts an expanded view of service bundle I, whichcan be a bundle that can include tubing, such as tubing A, which couldbe, for example, for delivering various inks, solvents and the like, toa printing system, such as printing system 1050 of FIG. 13A. Servicebundle 1 of FIG. 19A can additionally include electrical wiring, such aselectrical wire B or cabling, such as cable C, which can be a coaxial oroptical cable. Such tubings, wires and cables included in a servicebundle can be routed from the exterior to the interior to be connectedto various devices and apparatuses comprising an OLED printing system.As seen in the hatched area of FIG. 19A, void spaces in a service bundlecan create an appreciable dead volume D. In the schematic perspectiveview of FIG. 19B, when service bundle I is fed through duct II, inertgas III can continuously sweep past the bundle. The expanded sectionview of FIG. 20 depicts how effectively inert gas continuously sweepingpast bundled tubings, wires and cables can increase the rate of removalof occluded reactive species from dead volume formed in a servicebundle. The rate of diffusion of a reactive species A out of a deadvolume, indicated in FIG. 20 by the collective area occupied by speciesA, is inversely proportional to the concentration of the reactivespecies outside of the dead volume, indicated in FIG. 20 by thecollective area occupied by inert gas species B. That is, if theconcentration of a reactive species is high in a volume just outside thedead volume, then the rate of diffusion is decreased. If a reactivespecies concentration in such an area is continuously decreased from thevolume just outside dead volume space by a flow stream of inert gas,then by mass action, the rate at which the reactive species diffusesfrom the dead volume is increased. Additionally, by the same principle,inert gas can diffuse into the dead volume as occluded reactive speciesare effectively removed out of those spaces.

FIG. 21A is a perspective view of a rear corner of various embodimentsof gas enclosure assembly 101, with a phantom view through return duct1605 into the interior of gas enclosure assembly 101. For variousembodiments of gas enclosure assembly 101, rear wall panel 1640 can haveinset panel 1610, which is configured to provide access to, for example,an electrical bulkhead. A service bundle can be fed through a bulkheadinto a cable routing duct, such as duct 1632 shown in right wall panel1630, for which a removable inset panel has been removed to reveal aservice bundle routed into a first service bundle duct entry 636. Fromthere, the service bundle can be fed into the interior of gas enclosureassembly 101, and is shown in the phantom view through return duct 1605in the interior of gas enclosure assembly 101. Various embodiments of agas enclosure assembly for service bundle routing can have more than oneservice bundle entry, such as shown in FIG. 21A, which depicts a firstservice bundle duct entry 1634 and a second service bundle duct entry1636, for still another service bundle. FIG. 21B depicts an expandedview of first service bundle duct entry 1634 for a cable, wire, andtubing bundle. First service bundle duct entry 1634 can have opening1631, which is designed to form a seal with sliding cover 1633. Invarious embodiments, opening 1631 can accommodate a flexible sealingmodule, such as those provided by Roxtec Company for cable entry seals,which can accommodate various diameters of cable, wire, and tubing andthe like in a service bundle. Alternatively, top 1635 of sliding cover1633 and upper portion 1637 of opening 1631 may have a conformingmaterial disposed on each surface, so that the conforming material canform a seal around various-sized diameters of cable, wire, and tubingand the like in a service bundle fed through an entry, such as firstservice bundle duct entry 1634.

As depicted in FIG. 22 and FIG. 23 , the one or more fan filter unitscan be configured to provide a substantially laminar flow of gas throughthe interior of a gas enclosure assembly. According to variousembodiments of a circulation and filtration system for a gas enclosureassembly of the present teachings, one or more fan units are disposedadjacent a first interior surface of a gas enclosure assembly, and theone or more ductwork inlets are disposed adjacent a second, oppositeinterior surface of a gas enclosure assembly. For example, a gasenclosure assembly can comprise an interior ceiling and a bottominterior periphery, the one or more fan units can be disposed adjacentthe interior ceiling, and the one or more ductwork inlets can comprise aplurality of inlet openings disposed adjacent the bottom interiorperiphery that are part of a ductwork system, as shown in FIGS. 16-18 .

FIG. 22 is a cross-sectional view taken along the length of a gasenclosure system 505, according to various embodiments of the presentteachings. Gas enclosure system 505 of FIG. 22 can include a gasenclosure assembly 1100, which can house an OLED inkjet printing system2001, as well as circulation and filtration system 1500, gaspurification system 3130 (FIG. 12 and FIG. 13 ), and thermal regulationsystem 3140. Circulation and filtration system 1500 can include ductworkassembly 1501 and fan filter unit assembly 1502. Thermal regulationsystem 3140 can include fluid chiller 3142, which is in fluidcommunication with chiller outlet line 3141 and with chiller inlet line3143. Chilled fluid can exit fluid chiller 3142, flow through chilleroutlet line 3141, and be delivered heat exchangers, which for variousembodiments of a gas enclosure system, as shown in FIG. 22 , can belocated proximal to each of a plurality of fan filter units. Fluid tocan be returned from the heat exchangers proximal to the fan filter unitto chiller 3142 through chiller inlet line 3143 to be maintained at aconstant desired temperature. As previously discussed herein, chilleroutlet line 3141 and chiller inlet line 3143 are in fluid communicationwith a plurality of heat exchangers including first heat exchanger 1562,second heat exchanger 1564, and third heat exchanger 1566. According tovarious embodiments of gas enclosure system 505 as shown in FIG. 22 ,first heat exchanger 1562, second heat exchanger 1564, and third heatexchanger 1566 are in thermal communication with a first fan filter unit1552, a second fan filter unit 1554, and a third fan filter unit 1556,respectively, of fan filter unit assembly 1502 of circulation andfiltration system 1500.

In FIG. 22 , the many arrows depict flow of air in circulation andfiltration system 1500 provides low-particle filtered air within gasenclosure assembly 1100. In FIG. 22 , ductwork assembly 1501 can thatinclude first ductwork conduit 1573 and second ductwork conduit 1574 asdepicted in the simplified schematic of FIG. 22 . First ductwork conduit1573 can receive gas through a first ductwork inlet 1571 and can exitthrough a first ductwork outlet 1575. Similarly, second ductwork conduit1574 can receive gas through second ductwork inlet 1572 exit throughsecond ductwork outlet 1576. Additionally, as shown in FIG. 22 ,ductwork assembly 1501 separates inert gas that is recirculatedinternally through fan filter unit assembly 1502 by effectively definingspace 1580, which can be in fluid communication with gas purificationsystem 3130 via gas purification outlet line 3131 and gas purificationinlet line 3133. Such a circulatory system including various embodimentsof a ductwork system as described for FIGS. 16-18 , providessubstantially laminar flow, minimizes turbulent flow, promotescirculation, turnover and filtration of particulate matter of the gasatmosphere in the interior of the enclosure and provides for circulationthrough a gas purification system exterior a gas enclosure assembly.

FIG. 23 is a cross-sectional view taken along the length of a gasenclosure system 506, according to various embodiments of a gasenclosure system according to the present teachings. Like gas enclosuresystem 505 of FIG. 22 , gas enclosure system 506 of FIG. 23 can includea gas enclosure assembly 1100, which can house an OLED inkjet printingsystem 2001, as well as circulation and filtration system 1500, gaspurification system 3130 (FIG. 15 ), and thermal regulation system 3140.Circulation and filtration system 1500 can include ductwork assembly1501 and fan filter unit assembly 1502. For various embodiments of gasenclosure system 506, thermal regulation system 3140, which can includefluid chiller 3142 in fluid communication with chiller outlet line 3141and with chiller inlet line 3143, can be in fluid communication with aplurality of heat exchangers, for example, first heat exchanger 1562,and second heat exchanger1564, as depicted in FIG. 23 . According tovarious embodiments of gas enclosure system 506 as shown in FIG. 22 ,various heat exchangers, such as first heat exchanger 1562 and secondheat exchanger 1564 can be in thermal communication with circulatinginert gas by being positioned proximal to duct outlets, such as firstductwork outlet 1575 and second ductwork outlet 1576 of ductworkassembly 1501. In that regard, inert gas being returned for filtrationfrom duct inlets, such as duct inlets, such as first ductwork inlet 1571and second ductwork inlet 1572 of ductwork assembly 1501 can bethermally regulated prior to being circulated through, for example, afirst fan filter unit 1552, a second fan filter unit 1554, and a thirdfan filter unit 1556, respectively, of fan filter unit assembly 1502 ofFIG. 23 .

As can be seen from the arrows showing direction of inert gascirculation through the enclosure in FIG. 22 and FIG. 23 the fan filterunits can be configured to provide substantially laminar flow downwardlyfrom a top of the enclosure toward the bottom. Fan filter unitsavailable, for example, from Flanders Corporation, of Washington, N.C.,or Envirco Corporation of Sanford, N.C., may be useful for integrationinto various embodiments of a gas enclosure assembly according to thepresent teachings Various embodiments of a fan filter unit can exchangebetween about 350 cubic feet per minute (CFM) to about 700 CFM of inertgas through each unit. As shown in FIG. 22 and FIG. 23 , as the fanfilter units are in a parallel and not series arrangement, the amount ofinert gas that can be exchanged in a system comprising a plurality offan filter units is proportional to the number of units used.

Near the bottom of the enclosure the flow of gas is directed toward aplurality of ductwork inlets, indicated schematically in FIG. 22 andFIG. 23 as first ductwork inlet 1571 and second ductwork inlet 1572 ofductwork assembly 1501. As previously discussed herein for FIGS. 16-18 ,positioning the duct inlets substantially at the bottom of theenclosure, and causing downward flow of gas from upper fan filter unitsfacilitates good turnover of the gas atmosphere within the enclosure andpromotes thorough turnover and movement of the entire gas atmospherethrough the gas purification system used in connection with theenclosure. By circulating the gas atmosphere through the ductwork andpromoting laminar flow and thorough turnover of the gas atmosphere inthe enclosure using circulation and filtration system 1500, whichductwork assembly 1501 separates the inert gas flow for circulationthrough gas purification loop 3130, levels of each of a reactivespecies, such as water and oxygen, as well as each of a solvent can bemaintained in various embodiments of a gas enclosure assembly at 100 ppmor lower, for example 1 ppm or lower, for example, at 0.1 ppm or lower.

FIG. 24 is a front schematic view of gas enclosure system 507, which canbe a front schematic view of gas enclosure system 505 of FIG. 22 . InFIG. 24 , more detail can be seen of printing system 2001, which isdepicted enclosed within gas enclosure system 507. Various embodimentsof a gas enclosure system of the present teachings having a particlecontrol system can provide a low-particle zone proximal to a substrate,such as substrate 2050 of FIG. 24 , which can be supported by substratesupport apparatus 2200. Substrate support apparatus 2200 of printingsystem 2001 for various embodiments of a printing system can be a chuckor a floatation table. As previously discussed herein, variousembodiments of a gas circulation and filtration system according to thepresent teachings can include a ductwork assembly, such as ductworkassembly 1501 of FIG. 24 , as well as a fan filter unit assembly thatcan have a plurality of fan filter units, such as fan filter unitassembly 1502, in which fan filter unit 1552 is shown in the frontschematic view of FIG. 24 . The gas flow indicated by the arrows depictsa laminar flow of filtered gas proximal to substrate 2050. Recalling, alaminar flow environment can minimize turbulence and can create asubstantially low particle environment that can maintain airborneparticulate levels meeting the standards of International StandardsOrganization Standard (ISO) 14644-1:1999, as specified by Class 1through Class 5.

As will be discussed in more detail subsequently herein, for variousembodiments of a gas enclosure system of the present teachings, aneffective gas circulation and filtration system can be a part of aparticle control system. However, various particle control systems ofthe present teachings also guard against particle generation proximal toa substrate during a printing process. As depicted in FIG. 24 for gasenclosure assembly 1100 of gas enclosure system 507, substrate 2050 canbe proximal to various components of printing system 2001 that can beparticle-generating. For example, X,Z carriage assembly 2300 can includecomponents such as linear bearing systems that can be particlegenerating. Service bundle housing 2410 can contain particle-generatingservice bundles operatively connected from various apparatuses andsystem to a gas enclosure system including a printing system. Variousembodiments of a service bundle can include bundled optical cables,electrical cables, wires and tubing, and the like, for providingoptical, electrical, mechanical, and fluidic functions for variousassemblies and systems disposed within the interior of the gas enclosuresystem.

A gas enclosure system of the present teachings can have variouscomponents that provide a particle control system. Various embodimentsof a particle control system can include a gas circulation andfiltration system in fluid communication with particle-generatingcomponents that have been contained, so that such particle-containingcomponents can be exhausted into the gas circulation and filtrationsystem. For various embodiments of a particle control system,particle-generating components that have been contained can be exhaustedinto dead spaces, rendering such particulate matter inaccessible forrecirculation within a gas enclosure system. Various embodiments of gasenclosure systems of the present teachings can have a particle controlsystem for which various components can be intrinsically low-particlegenerating, thereby preventing particles from accumulating on asubstrate during a printing process. Various components of a particlecontrol system of the present teachings can utilize containment andexhausting of particle-generating components, as well as selection ofcomponents that are intrinsically low-particle generating to provide alow-particle zone proximal to a substrate.

According to various embodiments of a gas enclosure system used for OLEDprinting systems, the number of fan filter units can be selected inaccordance with the physical position of a substrate in a printingsystem during processing. As such, the number of fan filter units canvary according to the travel of a substrate through a gas enclosuresystem. For example, FIG. 25 is a cross-sectional view taken along thelength of a gas enclosure system 508, which is a gas enclosure systemsimilar to that depicted in FIG. 9 . Gas enclosure system 508 caninclude gas enclosure assembly 1100, which houses OLED inkjet printingsystem 2001 supported on gas enclosure assembly base 1320. Substratefloatation table 2200 of OLED printing system defines the travel overwhich a substrate can be moved through gas enclosure system 508 duringthe processing of a substrate. As such, fan filter unit assembly 1502 ofgas enclosure system 508 has an appropriate number of fan filter units;shown as 1551-1555, corresponding to the physical travel of a substratethrough inkjet printing system 2001 during processing. Additionally, theschematic section view of FIG. 25 depicts the contouring of variousembodiments of a gas enclosure, which can effectively decrease thevolume of inert gas required during an OLED printing process, and at thesame time provide ready access to the interior of gas enclosure assembly1100; either remotely during processing, for example, using glovesinstalled in various gloveports, or directly by various removable panelsin the case of a maintenance operation.

FIG. 26 depicts printing system 2002, according to various embodimentsof a printing system of the present teachings. Printing system 2002 canhave many of the features as previously described for printing system2000 of FIG. 10B. Printing system 2002 can be supported by printingsystem base 2101. Orthogonal to printing system base 2101 and mountedupon it can be first riser 2120 and second riser 2122, upon which bridge2130 can be mounted. For various embodiments of inkjet printing system2002, bridge 2130 can support a at least one X-axis carriage assembly2300 which can move in an X-axis direction relative to substrate supportapparatus 2250 through service bundle carrier run 2401. As will bediscussed in more detail subsequently herein, for various embodiments ofprinting system 2002, X-axis carriage assembly 2300 can utilize a linearair bearing motion system, which is intrinsically low-particlegenerating. According to various embodiments of a printing system of thepresent teachings, an X-axis carriage can have a Z-axis moving platemounted thereupon. In FIG. 26 , X-axis carriage assembly 2300 isdepicted with first Z-axis moving plate 2315. In various embodiments ofprinting system 2002, a second X-axis carriage assembly can be mountedon bridge 2130, which can also have a Z-axis moving plate mountedthereupon. In that regard, similarly to printing system 2000 of FIG.10B, for various embodiments of OLED inkjet printing system 2002, therecan be two carriage assemblies each with a printhead assembly, forexample, printhead assembly 2500 of FIG. 26 , as well as a secondprinthead assembly mounted on a second X,Z-axis carriage assembly (notshown). In various embodiments of printing system 2002, a firstprinthead assembly, such as printhead assembly 2500 of FIG. 26 , can bemounted on a first X,Z-axis carriage assembly, while a camera system forinspecting features of substrate 2050 can be mounted on a secondX,Z-axis carriage assembly (not shown). In various embodiments ofprinting system 2002 of FIG. 26 , a printhead assembly, such asprinthead assembly 2500 of FIG. 26 can be mounted on an X,Z-axiscarriage assembly, while either a UV lamp or a heat source for curing anencapsulation layer printed on substrate 2050 can be mounted on a secondX,Z-axis carriage assembly (not shown).

According to various embodiments of printing system 2002, substratesupport apparatus 2250 can be a floatation table, similar to floatationtable 2200 of printing system 2000 of FIG. 10B, in which a substrate canbe contained in the X,Y plane and a floatation table can be used to fixa stable Z-axis fly height. In various embodiments of printing system2002, substrate support apparatus 2250 can be a chuck. In variousembodiments of printing system 2002, a chuck can have top surface 2252for mounting a substrate. In various embodiments of printing system2002, top surface 2252 can support a top plate that can be replaceable,enabling easy exchangeability between different substrate sizes andtypes. In various embodiments of printing system 2002, a top plate canaccommodate multiple substrates of different sizes and types. In variousembodiments of printing system 2002 that can utilize a chuck as asubstrate support apparatus, a substrate can be securely held on a chuckduring a printing process using vacuum, magnetic or mechanical meansknown in the art. A precision XYZ motion system can have variouscomponents for the positioning of a substrate mounted on substratesupport apparatus 2250 relative to printhead assembly 2500, which caninclude Y-axis motion assembly 2355, as well as X,Z carriage assembly2300. Substrate support apparatus 2250 can be mounted on Y-axis motionassembly 2355 and can be moved on rail system 2360 using, for example,but not limited by, a linear bearing system; either utilizing mechanicalbearings or air bearings. For various embodiments of gas enclosuresystems, an air bearing motion system helps facilitation frictionlessconveyance in the Y-axis direction for a substrate placed on substratesupport apparatus 2250. Y-axis motion system 2355 can also optionallyuse dual rail motion, once again, provided by a linear air bearingmotion system or a linear mechanical bearing motion system. According tothe present teachings, other precision XYZ motion systems can be used,such as, for example, but not limited by, various embodiments of a3-axis gantry system. For example, various embodiments of a 3-axisgantry system can have an X,Z carriage assembly mounted on a gantrybridge for precision X,Z axis movement, where the gantry can be movedprecisely in the Y-axis direction.

In addition to a gas circulation and filtration system for maintaining alow-particle environment within a gas enclosure system, variousembodiments of a printing system, such as printing system 2000 of FIG.10B and printing system 2002 of FIG. 26 , can have additional componentsintegrated into a gas enclosure system that guard against particlegeneration proximal to a substrate during a printing process. Forexample, printing system 2000 of FIG. 10B and printing system 2002 ofFIG. 26 can have an intrinsically low-particle generating X-axis motionsystem, in which X,Z carriage assembly 2300 can be mounted andpositioned on bridge 2130 using linear air-bearing system 2320.Additionally, printing system 2000 of FIG. 10B and printing system 2002of FIG. 26 can have service bundle housing exhaust system 2400 forcontaining and exhausting particles generated from a service bundle.

According to the present teachings, a service bundle can include, by wayof non-limiting example, optical cables, electrical cables, wires andtubing, and the like. Various embodiments of a service bundle of thepresent teachings can be operatively connected to various devices andapparatuses in a gas enclosure system to provide optical, electrical,mechanical and fluidic connections required in the operation of, forexample, but not limited by, various devices and apparatuses associatedwith a printing system. Given the size and complexity of various servicebundles, various motion systems often require a service bundle carrierto manage a service bundle as it are moved along with the motion system.For various embodiments of a gas enclosure system of the presentteachings, a service bundle carrier can be flexible ties for tyingbundles of cabling, wires and tubing, and the like, together at regularintervals. For various embodiments of a gas enclosure system of thepresent teachings, a service bundle carrier can be a sheath or jacketthat can that can cover bundles of cabling, wires and tubing, and thelike, of a service bundle. In various embodiments of a gas enclosuresystem of the present teachings a service bundle carrier can moldedtogether bundles of cabling, wires and tubing, and the like, of aservice bundle. In various embodiments, a service bundle carrier can bea segmented or flexible chain that can support and carry bundles ofcabling, wires and tubing, and the like.

According to various embodiments of gas enclosure systems of the presentteachings, a service bundle housing, which can include a service bundlemanaged using a service bundle carrier, can contain particulate mattergenerated from a service bundle and service bundle carrier within aservice bundle housing. Additionally, as will be discussed in moredetail subsequently herein, movement of a service bundle carrier cancompress air volume in a piston-like fashion as it moves within aservice bundle housing, creating a positive pressure differentialbetween the interior service bundle housing and the surroundingenvironment exterior the service bundle housing that can allowparticulate matter formed from particle-generating components associatedwith the service bundle carrier to escape through, for example, theopening formed by a carrier run. Such particulate matter just proximal asubstrate has a substantial probability of contaminating a substratesurface before being swept away into a circulation and filtrationsystem. Accordingly, a service bundle housing exhaust system can be acomponent of various embodiments of a particle control system of a gasenclosure system that can contain and exhaust a service bundle housingin order to ensure a substantially low-particle printing environment.

As shown in FIG. 26 , and indicated by the dashed line, for variousembodiments of service bundle housing exhaust system 2400, servicebundle housing 2410 and service bundle housing exhaust plenum 2420 canbe a unitary assembly. For such embodiments, service bundle housingexhaust system 2400 can ensure that a positive pressure differentialbetween the inlet portions and the outlet portions of a service bundlehousing can be maintained for exhausting particles generated in servicebundle housing 2410 into a gas circulation and filtration system throughservice bundle housing exhaust plenum first duct 2422 and service bundlehousing exhaust plenum second duct 2424. Alternatively, for variousembodiments, service bundle housing exhaust system 2400 can includeservice bundle housing exhaust plenum 2420, which can be mounted to andin fluid communication with service bundle housing 2410. Service bundlehousing 2410 can contain particles generated by a service bundle thatcan include bundled optical cables, electrical cables, wires and tubing,and the like. Various embodiments of a service bundle of the presentteachings can provide a gas enclosure system, which can include aprinting system, with at least one of optical, electrical, mechanical,and fluidic functions for various assemblies and systems disposed withinthe interior of a gas enclosure. For various embodiments of printingsystem 2002, service bundle housing exhaust system 2400 can ensure thata positive pressure differential between the inlet portions and theoutlet portions of a service bundle housing can be maintained forexhausting particles contained in service bundle housing 2410 intoservice bundle housing exhaust plenum 2420. Service bundle housingexhaust plenum 2420 can be in fluid communication with a gas circulationand filtration system through service bundle housing exhaust plenumfirst duct 2422 and service bundle housing exhaust plenum second duct2424. Alternatively, service bundle housing exhaust plenum first duct2422 and service bundle housing exhaust plenum second duct 2424 can befitted with flexible exhaust hose, so that particles contained by aservice bundle housing can be exhausted through a service bundle housingexhaust plenum and directed via flexible exhaust hosing into a targeteddead space.

Furthermore, in addition to maintaining a positive pressure differentialbetween the inlet portions and outlet portions of a service bundlehousing exhaust system, for various embodiments of a service bundlehousing exhaust system, a relatively neutral or negative pressuredifferential can be further maintained between the interior of theservice bundle housing exhaust system and the surrounding environment.Such a relatively neutral or negative pressure differential that can bemaintained between the interior of the service bundle housing exhaustsystem and the surrounding environment can prevent the leakage ofparticles from the service bundle housing exhaust system through cracks,seams and the like. The leakage of particles through cracks, seems andthe like, just proximal to a substrate has a substantial probability ofcontaminating a substrate surface before being swept away into acirculation and filtration system.

FIG. 27A depicts a side section view of low-particle generating X-axismotion system 2320 according to various embodiments of the presentteachings. In FIG. 27A, low-particle generating X-axis motion system2320 is depicted in relationship to service bundle housing exhaustsystem 2400, which as shown in FIG. 27A, can have service bundle housing2410, and service bundle housing exhaust plenum 2420, which is in fluidcommunication with service bundle housing exhaust plenum first duct2422. Printing system 2002 can include base 2101, upon which substratesupport apparatus 2250 can be mounted. X,Z-carriage assembly 2300 can bemounted to bridge 2130. As can be seen in the section view presented inFIG. 27A, X-axis motion system 2320 can be a linear air bearing motionsystem, which is intrinsically low-particle generating. X-axis motionsystem 2320 can include a plurality of air bearing pucks 2330 andbrushless linear motor 2340. Service bundle carrier 2430 can be mountedto X,Z-carriage assembly 2300, and can be housed in service bundlehousing 2410. As depicted in FIG. 27A, service bundle housing exhaustplenum 2420 can be in fluid communication with service bundle housing2410, as well as being in fluid communication with a gas circulation andfiltration system through ductwork, such as service bundle housingexhaust plenum first duct 2422. In that regard, service bundle housing2410 can exhaust particles that are generated from various embodimentsof a service bundle. A service bundle according to the present teachingscan be a bundle that can include, for example, but not limited by,optical cables, electrical cables, wires and tubing, and the like, whichcan be managed using various embodiments of service bundle carrier 2430.Various embodiments of a service bundle of the present teachings can beoperatively connected to a printing system to provide various optical,electrical, mechanical and fluidic connections required to operate, forexample, but not limited by, a printing system. For various embodimentsof a gas enclosure of the present teachings, a service bundle carrier,such as service bundle carrier 2430, can be supported by service bundlehousing bottom side 2404. For various embodiments of a gas enclosure ofthe present teachings, a service bundle carrier, such as service bundlecarrier 2430, can be supported by a tray or a shelf.

FIG. 27B is an expanded view of FIG. 27A, which depicts low-particlegenerating X-axis motion system 2320 of printing system 2002 in moredetail. A plurality of air bearing pucks 2330 can be mounted to theinterior surface of X,Z-axis carriage assembly 2300. In that regard,various embodiments of low-particle generating X-axis motion system 2320can provide frictionless travel of X,Z-axis carriage assembly 2300 overbridge 2130. In FIG. 27A, first puck 2332 and second puck 2334 are shownproximal to first side 2132 of bridge 2130. Third puck 2336 of FIG. 27Bcan be proximal to top surface 2133 of bridge 2130, while forth puck2338 can be proximal to second side 2134 of bridge 2130. Brushlesslinear motor can include X,Z-axis carriage assembly magnet track 2342,which can be mounted on bridge 2130, and linear motor winding 2344,which can be mounted to X,Z-axis carriage assembly 2300. Encoder readhead 2346 can be associated with linear motor winding 2344 forpositioning linear motor 2340. In various embodiments of brushlesslinear motor 2340, encoder read head 2346 can be an optical encoder. Aswill be discussed in more detail subsequently herein, variousembodiments of low-particle X-axis motion system 2320 utilizing onfrictionless air bearing pucks can be integrated with variousembodiments of a compressor loop, as shown and described for FIG. 33 andFIG. 34 . Finally, as shown in FIG. 27B, service bundle housing exhaustsystem 2400 can include service bundle housing 2410, which can houseservice bundle carrier 2430. Service bundle housing exhaust system 2400can contain and exhaust can exhaust particles from service bundlehousing 2410, which can be generated a service bundle, which can bemanaged using a service bundle carrier, such as service bundle carrier2430.

FIG. 28A is a front perspective view of printing system 2003, which isshown having service bundle housing exhaust system 2400 mounted on topof bridge 2130. Various embodiments of printing system 2003 can havemany features as previously described for printing system 2000 of FIG.10B and printing system 2002 of FIG. 26 . For example, printing system2003 can be supported by printing system base 2101. Orthogonal toprinting system base 2101 and mounted upon it can be first riser 2120and second riser 2122, upon which bridge 2130 can be mounted. Forvarious embodiments of inkjet printing system 2003, bridge 2130 cansupport a at least one X-axis carriage assembly 2300 which can move inan X-axis direction relative to substrate support apparatus 2250 throughservice bundle carrier run 2401. According to various embodiments of aprinting system of the present teachings, X-axis carriage 2300 can haveZ-axis moving plate 2310 mounted thereupon. In that regard, variousembodiments of carriage assembly 2300 can provide precision X,Zpositioning of printhead assembly 2500 with respect to substrate supportapparatus 2250. In various embodiments of printing system 2003, a secondX-axis carriage assembly can be mounted on bridge 2130, which secondX-axis carriage can have a Z-axis moving plate mounted thereupon. Forembodiments of printing system 2003 having two X-axis carriageassemblies, either a printhead assembly can be mounted on each X,Z-axiscarriage, or various other devices, for example, as a camera, a UV lamp,and a heat source, as described for printing system 2000 of FIG. 10B and2002 of FIG. 26 , can be mounted on the two X,Z-axis carriageassemblies. According to various embodiments of printing system 2003,substrate support apparatus 2250 for supporting a substrate can be afloatation table, similar to floatation table 2200 of printing system2000 of FIG. 10B, or it can be a chuck, as previously described forprinting system 2002 of FIG. 26 . Printing system 2003 of FIG. 28A canhave an intrinsically low-particle generating X-axis motion system, inwhich X,Z carriage assembly 2300 can be mounted and positioned on bridge2130 using an air bearing linear slider assembly. For various printingsystems of the present teachings, an air bearing linear slider assemblycan wrap around the entirety of bridge 2130, allowing frictionlessmovement of X,Z carriage assembly 2300 on bridge 2130, as well providingthree point mounting that can preserve accuracy of travel for X,Zcarriage assembly 2300, as well as resisting skew.

Regarding the precise movement of a substrate relative to a printheadassembly, various embodiments of printing system 2003 of FIG. 28A canhave a precision XYZ motion system, which can include Y-axis motionassembly 2355, in addition to X,Z carriage assembly 2300. Substratesupport apparatus 2250 can be mounted on Y-axis motion assembly 2355 andcan be moved on rail system 2360 using, for example, but not limited by,a linear bearing system; either utilizing mechanical bearings or airbearings. For various embodiments of gas enclosure systems, an airbearing motion system helps facilitation frictionless conveyance in theY-axis direction for a substrate placed on substrate support apparatus2250. Y-axis motion system 2355 can also optionally use dual railmotion, once again, provided by a linear air bearing motion system or alinear mechanical bearing motion system. According to the presentteachings, other precision XYZ motion systems can be used, such as, forexample, but not limited by, various embodiments of a 3-axis gantrysystem. For example, various embodiments of a 3-axis gantry system canhave an X,Z carriage assembly mounted on a gantry bridge for precisionX,Z axis movement, where the gantry can be moved precisely in the Y-axisdirection.

As depicted in FIG. 28A, for various embodiments of printing system2003, service bundle housing exhaust system 2400 can be mounted overbridge 2130. Service bundle housing exhaust system 2400 can includeservice bundle housing exhaust plenum 2420, which can be mounted to andin fluid communication with service bundle housing 2410. Service bundlehousing 2410 can contain particles generated by service bundles that caninclude bundled optical cables, electrical cables, wires and tubing.Various embodiments of a service bundle of the present teachings canprovide a gas enclosure system including a printing system with at leastone of optical, electrical, mechanical, and fluidic functions forvarious assemblies and systems disposed within the interior. For variousembodiments of printing system 2003, service bundle housing exhaustsystem 2400 can ensure that a positive pressure differential between theinlet portions and outlet portions of a service bundle housing exhaustsystem can be maintained for exhausting particles contained in servicebundle housing 2410 into service bundle housing exhaust plenum 2420.Service bundle housing exhaust plenum 2420 can be in fluid communicationwith a gas circulation and filtration system through service bundlehousing exhaust plenum first duct 2422 and service bundle housingexhaust plenum second duct 2424. Alternatively, service bundle housingexhaust plenum first duct 2422 and service bundle housing exhaust plenumsecond duct 2424 can be fitted with flexible exhaust hose, so thatparticles contained by a service bundle housing can be exhausted througha service bundle housing exhaust plenum and directed via flexibleexhaust hosing into a targeted dead space.

For various embodiments of a service bundle housing exhaust system, inaddition to maintaining a positive pressure differential between theinlet portions and outlet portions of a service bundle housing exhaustsystem, a relatively neutral or negative pressure differential can befurther maintained between the interior of the service bundle housingexhaust system and the surrounding environment. Such a relativelyneutral or negative pressure differential that can be maintained betweenthe interior of the service bundle housing exhaust system and thesurrounding environment can prevent the leakage of particles from theservice bundle housing exhaust system through cracks, seams and thelike. The leakage of particles through cracks, seems and the like, justproximal to a substrate has a substantial probability of contaminating asubstrate surface before being swept away into a circulation andfiltration system.

FIG. 28B depicts an expanded partial cut-away front perspective view ofprinting system 2003. In FIG. 28B, X,Z carriage assembly 2300, which canutilize an air bearing linear slider assembly for positioning X,Zcarriage assembly 2300 carriage on bridge 2130. The movement of X,Zcarriage assembly 2300 moves in a X-axis direction over a distancedefined by service bundle carrier run 2401. Service bundle carrier run2401 is an opening that allows movement of optical cables, electricalcables, wires and tubing, and the like, which are bundled into a servicebundle, which is housed in service bundle housing 2410 and can beconnected, for example, but not limited by, to printhead assembly 2500.Given the size and complexity of various service bundles, various motionsystems often require a service bundle carrier to manage a servicebundle as it are moved along with the motion system. In that regard,service bundle carrier 2430 is shown housed in service bundle housing2410 of FIG. 28B. During printing, as a carriage assembly moves toprecisely position a printhead assembly in an X-axis direction relativeto a substrate positioned below it, the movement of service bundles thatcan include cables, wires and tubing, and the like, as well as themovement of a service bundle carrier itself, can create particulatematter just proximal to a substrate positioned below a service bundlehousing. Moreover the movement of a service bundle carrier can compressair volume in a piston-like fashion as it moves within a service bundlehousing, creating a positive pressure that can allow particulate matterformed from particle-generating components associated with a servicebundle carrier to escape through, for example, carrier run 2401. Suchparticulate matter just proximal a substrate has a substantialprobability of contaminating a substrate surface before being swept awayinto a circulation and filtration system. Accordingly, a service bundlehousing exhaust system can be a component of various embodiments of aparticle control system of a gas enclosure system that can ensure asubstantially low-particle printing environment.

In FIG. 28B, service bundle housing top surface 2402 is shown having aset of slots 2414, forming a slotted top surface. For variousembodiments of service bundle housing exhaust system 2400 of FIG. 28B,two requirements of such a system for ensuring that particulate matterformed from particle-generating components associated with a servicebundle carrier is swept into a circulation and filtration system: 1) theexhaust flow through a service bundle housing exhaust system should begreater than the volumetric change on the gas compression side of aservice bundle carrier as it move in a service bundle housing; and 2)there should be an even distribution of a constant exhaust flow toeffectively sweep a service bundle housing volume. Various embodiments aservice bundle housing exhaust system of the present teachings ensurethat these two requirements are met.

For example, as depicted in FIG. 29A, various embodiments of a servicebundle housing exhaust system can include service bundle housing 2410,which can be used to house service bundle carrier 2430. In FIG. 29A,service bundle carrier 2430 is depicted as a segmented flexiblechain-type of service bundle carrier, various other types of servicebundle carriers that can be used can behave similarly, thereby requiringthe use of various embodiments of a service bundle housing exhaustsystem of the present teachings. Service bundle carrier run 2401 is anopening that can allow particulate matter formed fromparticle-generating components associated with a service bundle carrierto escape a service bundle housing as a result of a positive pressurecreated by the movement of a service bundle carrier. Service bundlehousing exhaust plenum 2420 can be maintained at a positive pressurethat can ensure that particle-generating components associated with aservice bundle carrier can be exhausted through service bundle housingexhaust plenum first duct 2422 and service bundle housing exhaust plenumsecond duct 2424 and into a circulation and filtration system. A set ofservice bundle housing slots 2412 formed in service bundle housing topsurface 2402 as shown in FIG. 29A can ensure an even distribution of aconstant exhaust flow to effectively sweep the volume of service bundlehousing 2410.

Though service bundle housing slots 2412 are shown in FIG. 29A formedacross service bundle housing top side 2402, it can be appreciated thata set of slots can be located on various surfaces of a service bundlehousing, as depicted in FIG. 29B. As depicted in FIG. 29B, a set ofslots can be located on service bundle housing bottom side 2404 (setI.), service bundle housing first side 2406 (set II.), as well asservice bundle housing second side 2408 (set III.) Moreover, as depictedin FIG. 29C, though slots can be one type of opening for promoting theeven distribution of a constant exhaust flow to effectively sweep aservice bundle housing volume, openings having various shapes, aspectratios and locations can be used. As shown in FIG. 29C, substantiallycircular openings, such as first service bundle housing opening 2411 andsecond service bundle housing opening 2413 depicted as formed in servicebundle housing top side 2402 can be used to promote the evendistribution of a constant exhaust flow to effectively sweep a servicebundle housing volume. As depicted in FIG. 29C, an alternative placementfor substantially circular openings can be on ends of a service bundlehousing. In FIG. 29C, first service bundle housing opening 2411 andsecond service bundle housing opening 2413 depicted as formed in servicebundle housing first end 2415 and service bundle housing second end2417, respectively, can be used to promote the even distribution of aconstant exhaust flow to effectively sweep a service bundle housingvolume. Additionally, various embodiments of a service bundle housingmay have first service bundle carrier 2401 and a second service bundlecarrier run 2407. Service bundle housing top surface 2402 can have afirst set of slots 2412 and a second set of slots 2414, proximal tofirst service bundle carrier 2401 and a second service bundle carrierrun 2407, respectively, can be used to promote the even distribution ofa constant exhaust flow to effectively sweep a service bundle housingvolume. Finally, as shown in FIG. 27B, when a service bundle housingexhaust system includes a housing that is a single piece, a uniformdistribution of a constant exhaust flow can be promoted by considerationof an effective exhaust gas flow.

Various embodiments of a gas enclosure system of the present teachingsas depicted in FIG. 30A/30B through FIG. 32A/32B can have features aspreviously discussed herein with respect to FIG. 22 , FIG. 23 and FIG.24 regarding a gas circulation and filtration system that can promotelaminar flow and thorough turnover of the gas atmosphere in theenclosure, thereby ensuring that a substantially low-particleenvironment for airborne particulate matter can be maintained. Aspreviously discussed herein, a circulation and filtration system formaintaining low-particulate airborne specifications is one part of aparticulate control system for various embodiments of a gas enclosuresystem of the present teachings. A particle control system of thepresent teachings can also include a low-particle generating X-axismotion system utilizing air bearings, as well as utilizing a servicebundle housing exhaust system. Various embodiments of a low-particlegenerating X-axis motion system utilizing air bearings can substantiallyeliminate the generation of particulate matter. Further, variousembodiments of a service bundle housing exhaust system can be utilizedto ensure that particulate matter generated just proximal a substrateduring the printing process can contained and then swept into thecirculation and filtration system for removal. Additionally, as depictedin FIG. 30A/30B through FIG. 32A/32B, for controlling particulate matterformed by various devices, apparatuses, service bundles and the likethat can be positioned proximal a substrate during a printing process,various embodiments of a particle control system of the presentteachings can have a printhead assembly exhaust system.

FIG. 30A/30B depict gas enclosure system 509, while FIG. 31A/31B depictgas enclosure system 510, and FIG. 32A/32B depict gas enclosure system511, all of which can have features as previously described for FIG. 22, and FIG. 23 , as shown. Gas enclosure systems 509 through 511 can havecirculation and filtration system 1500, gas purification system 3130,and thermal regulation system 3140. Circulation and filtration system1500 can include ductwork assembly 1501 and fan filter unit assembly1502. Ductwork assembly 1501 can separate inert gas that is recirculatedinternally through fan filter unit assembly 1502 and externally to gaspurification system 3130 by effectively defining space 1580, which iseffectively a conduit in fluid communication with gas purificationsystem 3130. Space 1580 can be in fluid communication with a gaspurification system 3130 (FIG. 12 and FIG. 13 ) through gas purificationoutlet line 3131 and gas purification inlet line 3133. Such acirculatory system including various embodiments of a ductwork system asdescribed for FIGS. 16-18 , provides substantially laminar flow,minimizes turbulent flow, promotes circulation, turnover and filtrationof particulate matter of the gas atmosphere in the interior of a gasenclosure and provides for circulation through a gas purification systemexterior to a gas enclosure assembly.

Additionally, gas enclosure systems 509 through 511 as depicted in FIG.30A/30B through FIG. 32A/32B, respectively, can have printhead assemblyexhaust system 2600, which can be utilized to contain and exhaustparticulates formed by various assemblies associated with printingsystem 2003. For various embodiments of gas enclosure systems 509, 510and 511, printhead assembly exhaust system 2600 can house, for example,but not limited by carriage assembly 2300 onto which printhead assembly2500 can be affixed, as depicted in FIG. 30A/30B, FIG. 31A/31B, and FIG.32A/32B, respectively. Such a moving plate can utilize frictionbearings, which as previously discussed herein, can generate particlesduring operation of an OLED printing system. Additionally, as previouslydiscussed herein, a carriage assembly can be used to mount an apparatussuch as a UV lamp assembly or heat source assembly for curing anencapsulation layer. Either a UV lamp or a heat source may requirecooling using a fan.

Accordingly, printhead assembly exhaust system 2600 of gas enclosuresystems 509, 510 and 511 can be part of a particulate control systemused for containing and exhausting particulate matter formed by variousdevices, apparatuses, service bundles and the like that can bepositioned proximal a substrate during a printing process. Variousembodiments of a printhead assembly exhaust system, such as printheadassembly exhaust system 2600 of gas enclosure systems 509, 510 and 511can ensure that a positive pressure differential can be maintainedbetween the inlet portions and the outlet portions of a printheadassembly exhaust housing for exhausting particles generated by variouscomponents of a printhead assembly into a gas circulation and filtrationsystem. For various embodiments of a printhead assembly exhaust system,a positive pressure differential can be maintained between the inletportions and the outlet portions of a printhead assembly exhaust housingfor exhausting particles generated by various components of a printheadassembly into a dead space. As will be discussed in more detailsubsequently herein, a positive pressure differential for exhaustingparticles generated by various components of a printhead assembly can becreated, by use of fans as well as other system components, such as, butnot limited by, providing fluid communication between a printheadassembly exhaust housing and a circulation and filtration system.

For various embodiments of a printhead assembly exhaust system, inaddition to maintaining a positive pressure differential between theinlet portions and outlet portions of a printhead exhaust assembly, arelatively neutral or negative pressure differential can be furthermaintained between the interior of the printhead exhaust assembly andthe surrounding environment. Such a relatively neutral or negativepressure differential that can be maintained between the interior of theprinthead exhaust assembly and the surrounding environment can preventthe leakage of particles from the printhead exhaust assembly throughcracks, seams and the like. The leakage of particles through cracks,seems and the like, just proximal to a substrate has a substantialprobability of contaminating a substrate surface before being swept awayinto a circulation and filtration system.

As depicted in FIG. 30A and FIG. 30B, service bundle housing 2410 can besupported on bridge 2130 of printing system 2003. As previouslydiscussed herein in reference to printing system 2000 of FIG. 10B,carriage assembly 2300 can have components for controlling X-Z axismovement, including a Z-axis moving plate onto which printhead assembly2500 can be affixed. Printhead assembly exhaust system housing 2610 canbe in fluid communication with service bundle housing 2410, for example,but not limited by, printhead assembly exhaust system first conduit2612. Service bundle housing 2410 can be in fluid communication withductwork assembly 1501 through, for example, but not limited printheadassembly exhaust system second conduit 2614, which can be in fluidcommunication with second ductwork conduit 1574. Printhead assemblyexhaust system 2600 of FIG. 30A and FIG. 30B, which can containcomponents at risk of generating particles, such as a moving plate, canhave at least one fan, such as fan 2620, for promoting gas movementthrough printhead assembly exhaust system 2600 and into service bundlehousing 2410. In that regard, the entirety of air contained in printheadassembly exhaust system 2600 and service bundle housing 2410 can beeffectively filtered by circulation and filtration system 1500, asdepicted in FIG. 30A.

According to the present teachings, particulate matter collecting in adead space area away from a substrate mounted on substrate supportapparatus cannot be recirculated within a gas enclosure system. In thatregard, various embodiments of a gas enclosure system depicted in FIG.31A/31B and FIG. 32A/32B may utilize directing particulate matter into aductwork system, as well as into dead space. During regular gasenclosure system maintenance, such particulate matter can be removedfrom a dead space.

In that regard, for various embodiments of a gas enclosure system, suchas gas enclosure system 510 of FIG. 31A and FIG. 31B, service bundlehousing 2410 can be in fluid communication with circulation andfiltration system 1500. As depicted in FIG. 31B, printhead assemblyexhaust system housing 2610 can be in fluid communication with servicebundle housing 2410, for example, but not limited by, printhead assemblyexhaust system first conduit 2612. Service bundle housing 2410 can be influid communication with printhead assembly exhaust system secondconduit 2614, which can have an outlet end proximal to second ductworkinlet 1572 of ductwork assembly 1501. In that regard, printhead assemblyexhaust system second conduit 2614 can be in fluid communication withductwork assembly via second ductwork conduit 1574. Printhead assemblyexhaust system first conduit 2612 can have a fan, such as fan 2620, forpromoting gas movement through printhead assembly exhaust system firstconduit 2612. Additionally, printhead assembly exhaust system secondconduit 2614 can have fan 2622 for promoting gas movement throughprinthead assembly exhaust system 2614, so that particles contained byprinthead assembly exhaust system 2600 and service bundle housing 2410can be effectively filtered by circulation and filtration system 1500,as depicted in FIG. 31A. For various embodiments of a gas enclosuresystem, such as gas enclosure system 510 of FIG. 31A and FIG. 31B, anyparticulate matter not streamed into second ductwork inlet 1572 wouldhave a trajectory towards dead space 1590.

As depicted for gas enclosure system 511 of FIG. 32A and FIG. 32B,service bundle housing 2410 can be in fluid communication withcirculation and filtration system 1500. As depicted in FIG. 32B,printhead assembly exhaust system housing 2610 can be in fluidcommunication with service bundle housing 2410, for example, but notlimited by, printhead assembly exhaust system first conduit 2612, whichcan have a fan, such as fan 2620, for promoting gas movement throughprinthead assembly exhaust system first conduit 2612. Service bundlehousing 2410 can be in fluid communication with printhead assemblyexhaust system second conduit 2614, which can have filter head 2616.Filter head 2616 can filter particulate matter emanating from printheadassembly exhaust system 2600 and into service bundle housing 2410, anddirect the low-particle gas stream flowing from filter head 2616directly into gas enclosure system 511. In that regard, printheadassembly exhaust system second conduit 2614 can exhaust low-particle gasinto gas enclosure system 511, which can then be circulate throughcirculation and filtration system 1500 of gas enclosure system 511, asdepicted in FIG. 32A.

Various gas enclosure systems of the present teachings, such as gasenclosure system 501 of FIG. 12 and gas enclosure and gas enclosuresystem 502 of FIG. 13 , can utilize various gas enclosures, for example,but not limited by, gas enclosure 100 of FIG. 1A and gas enclosure 1000of FIG. 9 . Further, various gas enclosures, such as gas enclosure 100of FIG. 1A and gas enclosure 1000 of FIG. 9 , can house a variousprinting systems, such as printing system 2000 of FIG. 10B, printingsystem 2002 of FIG. 26 and FIG. 2003 of FIG. 28A. For gas enclosuresystems and methods of the present teachings, monitoring a controlledenvironment of a gas enclosure is an important aspect of maintaining acontrolled environment of a gas enclosure.

One parameter of a controlled environment that can be monitored iseffectiveness of the control of particulate matter. System validation aswell as ongoing in situ system monitoring can be performed for bothairborne and on-substrate particle monitoring.

A determination of airborne particulate matter can be performed forvarious embodiments of a gas enclosure system before a printing processfor system validation, using, for example, a portable particle countingdevice. In various embodiments of a gas enclosure system, adetermination of airborne particulate matter can be performed as anongoing quality check in situ while a substrate is printed. For variousembodiments of a gas enclosure system, a determination of airborneparticulate matter can be performed for system validation before asubstrate is printed and additionally in situ while a substrate isprinted.

FIG. 33 depicts a device for measuring airborne particulate matter.According to the present teachings, various embodiments of particlecounter 800 of FIG. 33 can be hand held or otherwise portable. Asdepicted in FIG. 33 , particle counter 800 can have power button 810, aswell as display 812 for real-time visual monitoring of variousparameters, such as the particle size being monitored, as well as thecurrent count of particulate matter of that size. Portable particlecounters of the present teachings can have multiple channels formonitoring several particle size ranges during an analysis. By way of anon-limiting example, display 812 of particle counter 800 is depictedmonitoring three distinct particle size ranges. For various embodimentsof systems and methods of the present teachings, monitoring particles inthe size range of about ≥0.3 □m can be useful for monitoring systemquality, as a sudden spike in particles in that size range may be anearly indication, for example, of a malfunction in the filtration systemof a gas enclosure system. Various embodiments of a particle counteraccording to the present teachings can have a cable or wirelessconnection (not shown) from the particle counter to, by way of anon-limiting example, a computer, which can provide ongoing collectionand storage of data from the particle counter. Particle counter 800 canhave inlet nozzle 814 for drawing an air sample into particle counter800. Various embodiments of a particle counter for measuring airborneparticulate matter can have an isokinetic sampling probe, such assampling probe 816 of FIG. 33 , which can reduce count errors related tothe sample flow velocity and the aerodynamics of particles; particularlysmall particles. To obtain a result that is accurate with respectparticulate matter in a flow stream, the flow of the sample through thesampling system should be such that the velocity at the sampling pointinlet is the same as the velocity of flow stream gas at that point. Anisokinetic sampling probe can have inlet probe 815, which can beattached to inlet nozzle 814, using sampling probe connector 817. Forvarious embodiments of sampling probe 816, sampling probe connector 817can be a section of flexible tubing. For sampling in various embodimentsof a gas enclosure system of the present teachings, inlet probe 815 ofsampling probe 816 can face directly into the air flow.

Though various commercial particle counters can be based on variousmeasurement principles that can include light blocking, direct imagingand light scattering, the measurement, measurement based on lightscattering from a particle is well suited to yield information ofinterest, including particle size. In principle, particle size down toabout 1 nm can be determined using light scattering.

FIG. 34 is a schematic depiction of particle counter detector 830 basedon light scattering. A particle counter detector based on lightscattering can have a source of electromagnetic radiation of knownwavelength range of known wavelength, such as light source 820. Forvarious embodiments of particle counter detector 830, light source 820can be a laser source emitting light of a known wavelength. For variousembodiments of a particle counter; especially for, but not exclusivelyfor handheld and portable particle counting devices, light source 820can be a light-emitting diode (LED) that emits light of a knownwavelength of between about 600 nm to about 850 nm. Emitted source light821 can be focused at detection area 822 of flow path 824, which isdepicted in FIG. 34 as a top section view. Any particle in detectionarea 822 can scatter light, creating forward scattered light 823 orlight scattered in a number of angular directions, including orthogonalto the direction of emitted source light 821, as depicted for light path825. Light scattered orthogonally by a particle in detection area 822can be focused using focusing lens 826, and can be filtered using atleast one optical filter, for example, a spatial or an optical bandpassfilter, or combinations thereof, before being detected by detector 828,which can be various types of a photometer detectors, for example, basedon photodiode technology. Various embodiments of a particle counter canbe calibrated using a calibration standard, such as an aerosol havingparticulate matter of defined distribution of particles in various sizeranges, where each size range has a defined concentration.

For example, various commercial particle counters based on lightscattering can detect airborne particle sizes in the range of about ≥0.3μm to about ≥10 μm, and report number of particles of a specified sizeper volume of air; generally as cubic feet or cubic meters. Variouscommercial particle counters can count up to between about 1 million toabout 3 million particles of a specified size. In that regard, variouscommercial calibration standards can have a distribution of particlescovering of about ≥0.3 μm to about ≥10 μm, for example a bimodal ortrimodal distribution of species covering that range, where eachpopulation of particles has a defined concentration that can be up to adetection limit of about 1 million to about 3 million particles. Aspreviously discussed herein, various particle counters for determiningairborne particulate matter can have multiple channels for monitoring anumber of particle size ranges. Though shown with one light source andone detector, various embodiments of a particle counter for determiningairborne particulate matter can have more than one light source, andmultiple detectors at various positions for monitoring light scatteredat various angles. Such airborne particle counters can monitor andreport over a large dynamic particle size range for airborne particulatematter of about ≥0.1 μm to about ≥10.0 μm.

FIG. 35 is a schematic representation using particle counter icons 800Athrough 800D and is meant to convey where various embodiments of aparticle counting device can be located with respect to a low-particlezone of a printing system, which is proximal to a substrate. Gasenclosure system 512 of FIG. 35 can have components as previouslydescribed herein for gas enclosure systems 500-511, including, but notlimited by, gas enclosure assembly 1100, thermal regulation system 3140that can be integrated with a circulation and filtration system, asindicated by fan filter unit 1552, which is proximal to heat exchanger1562. Gas enclosure system 512 of FIG. 35 can have outlet line 3131 andinlet line 3133 to a gas purification system (not shown), as well ashousing printing system 2004. Printing system 2004 can have base 2101,upon which substrate support apparatus 2200 can be mounted. Printingsystem 2004 can additionally have bridge 2130, which can have firstcarriage assembly 2300A and second carriage assembly 2300B mountedthereupon. Printing system 2004 can also have service cable housing 2410for housing a service cable (not shown).

Regarding FIG. 35 , at least one particle counter can be positioned ormounted on, for example, service bundle housing 2410, as indicated byparticle counter icon 800A, depicted in the laminar flow stream of fanfilter unit 1552. A particle counter so positioned in a laminar flowstream of gas from a fan filter unit can allow for monitoring theeffectiveness of a filtration system of a gas enclosure system.Additionally, bridge 2130 of printing system 2004 can support first X,Zaxis carriage assembly 2300A, to which printhead assembly 2500 can bemounted. Second X,Z axis carriage assembly 2300B can have at least oneparticle counter mounted thereupon, as indicated by particle countericon 800B. Monitoring at a position proximal to various printing devicesand apparatuses such as carriage assemblies may be useful monitoringvarious sources of particle generation, such as a service bundle. Aparticle counter mounted as depicted by particle counter icon 800C couldbe useful for procedure development, and gas enclosure system validationruns. A particle counter mounted as depicted by particle counter icon800D could be useful for procedure development, and gas enclosure systemvalidation runs as well as in situ monitoring of airborne particulatematter during a printing process.

According to various systems and methods of the present teachings, aparticle counting device could be mounted or placed on a substratesupport apparatus to measure particles under defined conditions in animmediate area where a substrate can be located during printing. Forexample, as depicted in FIG. 35 , particle counter could be placed ormounted on top of substrate support apparatus 2200, as indicated by theposition of particle counter icon 800C. In various embodiments ofsystems and methods of the present teachings, monitoring of particulatematter using a particle counter placed or mounted on top of a substratesupport apparatus can be done for various types of procedure developmentor gas enclosure system validation run studies. By way of anothernon-limiting example, a particle counter could be mounted on a side ofsubstrate support apparatus 2200 as indicated by the position ofparticle counter icon 800D. By using a particle counter with a samplingprobe having a flexible connector, such as particle counter 800 of FIG.33 , having sampling probe 816, a particle counter mounted to the sideof a substrate support apparatus can have a sampling probe placed justat the height of a substrate.

A particle counter mounted on a side of a substrate support apparatus,as indicated by particle counter icon 800D, could be useful forprocedure development, and gas enclosure system validation runs, as wellas in situ monitoring of airborne particulate matter during a printingprocess. For example, in FIG. 36 , printing system 2003, as previouslydescribed for FIG. 26 and FIG. 28A, can have X-axis carriage assembly2300 mounted on bridge 2130, which can also include Z-axis moving plate2310 for the Z-axis positioning of printhead assembly 2500. In thatregard, various embodiments of carriage assembly 2300 can provideprecision X,Z positioning of printhead assembly 2500 with respect tosubstrate 2050. For various embodiments of printing system 2003, haveX-axis carriage assembly 2300 can utilize a linear air bearing motionsystem, which is intrinsically low-particle generating. Printing system2003 of FIG. 36 can have can have service bundle housing exhaust system2400 for containing and exhausting particles generated from servicebundles, which can include service bundle housing 2410 for housing aservice bundle. According to the present teachings, a service bundle canbe operatively connected to a printing system to provide variousoptical, electrical, mechanical and fluidic connections required tooperate various devices and apparatuses in a gas enclosure system, forexample, but not limited by, various devices and apparatuses associatedwith a printing system. Printing system 2003 of FIG. 36 can havesubstrate support apparatus 2250 for supporting substrate 2050, whichcan be positioned with precision in the Y-axis direction using Y-axispositioning system 2355. Both substrate support apparatus 2250 andY-axis positioning system 2355 are supported by printing system base2101.

For printing system 2003 of FIG. 36 , a precision XYZ motion system canhave various components for the positioning of a substrate mounted onsubstrate support apparatus 2250 relative to printhead assembly 2500,which can include Y-axis motion assembly 2355, as well as X-axiscarriage assembly 2300. Substrate support apparatus 2250 can be mountedon Y-axis motion assembly 2355 and can be moved on rail system 2360using, for example, but not limited by, a linear bearing system; eitherutilizing mechanical bearings or air bearings. For various embodimentsof gas enclosure systems, an air bearing motion system helpsfacilitation frictionless conveyance in the Y-axis direction for asubstrate placed on substrate support apparatus 2250. Y-axis motionsystem 2355 can also optionally use dual rail motion, once again,provided by a linear air bearing motion system or a linear mechanicalbearing motion system. According to the present teachings, otherprecision XYZ motion systems can be used, such as, for example, but notlimited by, various embodiments of a 3-axis gantry system. For example,various embodiments of a 3-axis gantry system can have an X,Z carriageassembly mounted on a gantry bridge for precision X,Z axis movement,where the gantry can be moved precisely in the Y-axis direction.

According to various systems and methods of the present teachings,printing system 2003 of FIG. 36 can have a particle counter 800 mountedto a side of substrate support apparatus 2250, so that isokinetic sampleprobe 816 is at about the same height as substrate 2050. Though FIG. 36depicts particle counter 800 on a front side of substrate supportapparatus, it is possible to mount one or more particle counters atvarious locations of a substrate support apparatus to effectivelymonitor airborne particulate matter proximal to a substrate.Additionally, for various embodiments of systems and methods, additionalparticle counters can be mounted or placed in other locations, asdescribed for FIG. 35 .

According to various embodiments of a gas circulation and filtrationsystem contained in various embodiments of a gas enclosure system of thepresent teachings, continuous measurement of airborne particles can bedone in a gas enclosure system. In various embodiments of a gasenclosure system of the present teachings, such measurements can beperformed in a fully automated mode and continuously reported to an enduser, for example, through a graphical user interface (GUI). In variousembodiments of a gas enclosure system of the present teachings,measurement of airborne particulate matter can be done in targetedlocations of interest, as depicted in FIG. 35 . The output from each ofa particle counter located in a gas enclosure can be reported to an enduser, for example, through a GUI. For example, a target area of interestcan be airborne particulate matter just proximal to a substrate over asubstrate support apparatus, such as a chuck or a floatation table, asdepicted in FIG. 36 .

In that regard, continual monitoring of various embodiments of a gasenclosure system of the present teachings has confirmed that particlesof the size of about ≥2 μm can be maintained at less than about 1particle of that size range over a print cycle. For various embodimentsof a gas enclosure system of the present teachings, particles of thesize of about ≥2 μm can be maintained at less than about 1 particle ofthat size range over at least about a 24 hour period. For variousembodiments of a gas enclosure system of the present teachings,particles of the size of about ≥0.3 μm can be maintained at less thanabout 3 particles of that size range over a print cycle. For variousembodiments of a gas enclosure system of the present teachings,particles of the size of about ≥0.3 μm can be maintained at less thanabout 3 particles of that size range over at least about a 24 hourperiod. According to the present teachings, measurements of particulatematter taken from different locations in various embodiments of a gasenclosure system of the present teachings over a duration of at leastabout 24 hour period have been reported as an average of 0.001 particlesof ≥2 μm and 0.02 particles of ≥0.5 μm.

For example, FIG. 37A and FIG. 37B depict the results of long termmeasurements taken in various embodiments of a gas enclosure system ofthe present teachings. In FIG. 37A, two tests taken on different daysare depicted. Such tests were performed in a gas enclosure system, suchas those shown in FIG. 12 and FIG. 13 , which was maintained in an inertnitrogen environment. The measurements were performed proximal to asubstrate support apparatus, such as a chuck or a floatation table, asdepicted in FIG. 36 . During the testing period, the gas enclosuresystem was under continuous use for sequences including printing,maintenance and idle. In Test 1, the duration of real-time measurementwas about 16 hours. During that period, a total of 2 particles of thesize of about ≥2 μm were measured; 1 at about 5 hours and 1 near the endof the test period. For Test 2, which had a duration of about 10 hours,no particles of this size range were measured. In FIG. 37B, themeasurements for Test 3, performed on the system on still another dayover more than an 8 hour period, are depicted for particles of the sizeof about ≥0.5 μm. During this test period, a gas enclosure assemblywindow, such as window 130 of FIG. 1A, was opened periodically, at about2 hours (reference number I.), at about 6.5 hours (reference number II.)and at about 7 hours (reference number III.). During these periods oftransient gas enclosure system exposure to the ambient environment, themeasurement of particulate matter can be observed to spike and then berapidly re-established to a baseline value of about ≤1 particle in thatsize range.

For various embodiments of systems and methods of the present teachings,airborne particulate matter measured in a gas enclosure system can beless than about 3 particles/ft³ for particles about ≥0.3 μm, less thanabout 1 particle/ft³ for particles about ≥0.5 μm, and less than about 0particles/ft³ for particles about ≥1.0 μm. In that regard, variousembodiments of a gas circulation and filtration system can be designedto provide a low particle inert gas environment for airborneparticulates meeting the standards of International StandardsOrganization Standard (ISO) 14644-1:1999, “Cleanrooms and associatedcontrolled environments—Part 1: Classification of air cleanliness,” asspecified by Class 1 through Class 5, and may even meet or exceed thestandards set by Class 1.

Such rapid system recovery by various embodiments of a circulation andfiltration system of the present teachings as demonstrated in the datapresented for FIG. 37B is additionally depicted in the graph of FIG. 38. In FIG. 38 , particles of the size of about ≥2 μm were monitoredproximal to a substrate support apparatus, such as a chuck or aflotation table. As can be seen the graph of FIG. 38 , recover back to abaseline level of about ≤1 particle in that size range occurred in lessthan 3 minutes.

A determination of an on-substrate distribution of particulate matter ona substrate can be performed for various embodiments of a gas enclosuresystem before a substrate is printed for system validation, using, forexample, a test substrate. In various embodiments of a gas enclosuresystem, a determination of an on-substrate distribution of particulatematter can be performed as an ongoing quality check in situ while asubstrate is printed. For various embodiments of a gas enclosure system,a determination of an on-substrate distribution of particulate mattercan be performed for system validation before a substrate is printed andadditionally in situ while a substrate is printed.

FIG. 39 depicts an on-substrate detection scheme based on lightscattering, which can have essentially the same components as previouslydescribed for particle counter detector 830 of FIG. 34 in regard todetection systems for airborne particulate matter.

In FIG. 39 , on-substrate particle counter detection system 860 based onlight scattering can have a source of electromagnetic radiation of knownwavelength range of known wavelength, such as light source 850. Forvarious embodiments of on-substrate particle counter detection system860, light source 850 can be a laser source emitting light of a knownwavelength between about 600 nm to about 850 nm. Emitted source light851 is depicted by ray tracing to interact with particle 852 onsubstrate 854. For various embodiments of systems and methods of thepresent teachings, a substrate can be a test substrate, such as asilicon wafer. Given the history of on-substrate particle determinationsthat have evolved from the semiconductor industry, particledeterminations on silicon wafers are well-accepted testing methods.Further, a silicon wafer can have attributes such as having a reflectivesurface, which is preferable for an on-substrate detection system basedon light scattering. Additionally, a silicon wafer is a substantiallyconductive material, so that it can be grounded. Having a substratesurface that is electrical neutral is important for getting unbiasedsampling of on-substrate particle deposition. As it is not uncommon forparticulate matter to carry a charge, a charged surface could therebyrender a false positive or false negative result, depending on whetherthe interaction between a charged particle and a charged surface isattractive or repulsive.

With respect to a substrate having a reflective surface, such as asilicon wafer test substrate, emitted source light 851 can be reflected,as shown by reflected light rays 853 and it can also interact withparticle 852 on substrate surface 854 to produce scattered light, asdepicted by scattered light 855. As previously discussed herein for thecase of an airborne particle detection based on light scattering, suchas particle counter detector 830 of FIG. 34 , light can be scattered ina number of angular directions, including orthogonal to the direction ofemitted source light 851, as depicted for scattered light 855 fallingwithin light path I. Focusing lens 856 can focus light scatteredorthogonal to the direction of emitted source light 851 by particle 852,as depicted by light path II towards at least one optical filter, suchas filter 857. Optical filter 857 can be for example, a spatial or anoptical bandpass filter, or an additional filter can be added to providecombinations thereof. Finally, light scattered orthogonal to thedirection of emitted source light 851 can be detected by detector 858,which can be various types of a photometer detectors, for example, basedon photodiode technology. According to various embodiments of systemsand methods of the present teachings, using an on-substrate particlecounter detection system, such as on-substrate particle counterdetection system 860 of FIG. 39 , a report including the number ofparticles of a particle size, as well as a the location of everyparticle detected on the surface can be provided to an end-user.

With respect to testing protocols for on-substrate particledetermination, for example, but not limited by, for system validation,silicon test wafers that have been analyzed and then sealed can beobtained with a report of the size and location of particles determinedfor each test wafer. Test wafers can be obtained as individually sealedor in cassette. According to various systems and methods of the presentteachings, a cassette of witness wafers can be sealed within thecassette housing and then the cassette housing can be sealed with aremovable sealing material, such as a sealed polymeric pouch. Forvarious testing protocols for on-substrate particle determination forgas enclosure system validation, a cassette of witness wafers can beplaced into a gas enclosure system either by an end-user or robotically.For example, a cassette can be placed in an auxiliary enclosure, aspreviously described herein, either by an end-user or robotically andthe auxiliary enclosure can be placed through a recovery process untilthe gas environment is brought into specification with respect toreactive gases. The cassette can be transferred into a printing systemenclosure, either by an end-user or robotically. Once the sealedcassette is within a gas enclosure system, the cassette of witness wafercan be unsealed and the cassette housing can be opened to readily accessa wafer.

In reference to FIG. 40 , printing system 2003 depicted having testwafer 854 can have all of the elements previously described for printingsystem 2002 of FIG. 26 , as well as printing system 2003 of FIG. 28A andFIG. 36 . For example, but not limited by, in FIG. 40 , printing system2003, as previously described for FIG. 26 , FIG. 28A and FIG. 36 , canhave X-axis carriage assembly 2300 mounted on bridge 2130, which canalso include Z-axis moving plate 2310 for the Z-axis positioning ofprinthead assembly 2500. In that regard, various embodiments of carriageassembly 2300 can provide precision X,Z positioning of printheadassembly 2500 with respect to a substrate positioned on substratesupport 2250. For various embodiments of printing system 2003, X-axiscarriage assembly 2300 can utilize a linear air bearing motion system,which is intrinsically low-particle generating. Printing system 2003 ofFIG. 40 can have can have service bundle housing exhaust system 2400 forcontaining and exhausting particles generated from service bundles,which can include service bundle housing 2410 for housing a servicebundle. Printing system 2003 of FIG. 40 can have substrate supportapparatus 2250 for supporting a substrate, which can be positioned withprecision in the Y-axis direction using Y-axis positioning system 2355.Both substrate support apparatus 2250 and Y-axis positioning system 2355are supported by printing system base 2101. Substrate support apparatus2250 can be mounted on Y-axis motion assembly 2355 and can be moved onrail system 2360 using, for example, but not limited by, a linearbearing system; either utilizing mechanical bearings or air bearings.For various embodiments of gas enclosure systems, an air bearing motionsystem helps facilitation frictionless conveyance in the Y-axisdirection for a substrate placed on substrate support apparatus 2250.Y-axis motion system 2355 can also optionally use dual rail motion, onceagain, provided by a linear air bearing motion system or a linearmechanical bearing motion system.

Test wafer 854 of FIG. 40 can be placed on substrate support apparatus2250 of printing system 2003. Substrate support apparatus 2250 can bepositioned proximal to bridge 2130, in a variety of positions that cansimulate where a substrate can be positioned during a printing process.A test wafer can have an edge exclusion zone, in which particledetermination is not performed post testing, as an edge exclusion zoneis zone where handling is performed, which can introduce contaminationat the wafer edge. According to various testing protocols foron-substrate particle determination for gas enclosure system validation,an edge exclusion zone can be between about 1 cm to about 2 cm in widtharound the perimeter of a wafer and measured from the wafer edge. Forvarious testing protocols for on-substrate particle determination forgas enclosure system validation, a series of on-substrate particledetermination can be made to assess the state of a gas enclosure systemhousing a printing system. First, a background test can be performed, inwhich a statistical number of test wafers can be taken out by handling atest substrate just at the edge exclusion zone and placed then placedback into the cassette. In a next static test, a statistical number oftest wafers can be taken out by handling a test substrate just at theedge exclusion zone and then exposed to the tool environment for a setduration of time, such as for a duration of a printing process, withoutany actuation of any apparatus or device within the gas enclosuresystem. In that regard, test wafers in the static set of test wafers arein a static printing environment. A set of test wafers for a statictest, can then be moved back into the cassette housing. In a print test,a statistical number of test wafers can be taken out by handling a testsubstrate just at the edge exclusion zone and then exposed to the toolenvironment for the duration a printing process, without any actuationof ink ejection, but with full actuation of apparatus or device withinthe gas enclosure system. For example, printhead assembly 2500 mountedon carriage assembly 2300 can move relative to test wafer 854 mounted onsubstrate support apparatus of printing system 2003 depicted in FIG. 40, simulating a true print cycle. In that regard, the test wafers in aprint set of test wafers are in a static printing environment. The setof test wafers for a print test can then be moved back into the cassettehousing.

Once the testing protocol including background testing, static testing,and print testing, have been completed, the cassette housing can beresealed, and the cassette can be removed from the printing systemenclosure for testing. For example, a sealed cassette with the series oftest wafers can be placed in an auxiliary enclosure. When the printingsystem enclosure is sealably isolated from the auxiliary enclosure aspreviously described herein, the auxiliary enclosure can be opened tothe surrounding environment and the sealed cassette with the test waferscan be retrieved and sent for analysis. All process steps for variousembodiments an on-substrate particle determination testing protocol ofthe present teachings can be performed either by an end-user orrobotically, or combinations thereof. Finally, the auxiliary enclosureclosed and can be placed through a recovery process until the gasenvironment is brought into specification with respect to reactivegases.

Various imaging systems and methods of the present teachings can beutilized for in situ on-substrate particulate matter determination, aswell as for performing system validation procedures. In reference toFIG. 41 , printing system 2004 can have all of the elements previouslydescribed for printing system 2002 of FIG. 26 , as well as printingsystem 2003 of FIG. 28A, FIG. 36 , and FIG. 40 . For example, but notlimited by, printing system 2004 of FIG. 41 can have service bundlehousing exhaust system 2400 for containing and exhausting particlesgenerated from a service bundle. Service bundle housing exhaust system2400 of printing system 2004 can include service bundle housing 2410,which can house a service bundle. According to the present teachings, aservice bundle can be operatively connected to a printing system toprovide various optical, electrical, mechanical and fluidic connectionsrequired to operate various devices and apparatuses in a gas enclosuresystem, for example, but not limited by, various devices and apparatusesassociated with a printing system. Printing system 2004 of FIG. 41 canhave substrate support apparatus 2250 for supporting substrate 2050,which can be positioned with precision in the Y-axis direction usingY-axis positioning system 2355. Both substrate support apparatus 2250and Y-axis positioning system 2355 are supported by printing system base2101. Substrate support apparatus 2250 can be mounted on Y-axis motionassembly 2355 and can be moved on rail system 2360 using, for example,but not limited by, a linear bearing system; either utilizing mechanicalbearings or air bearings. For various embodiments of gas enclosuresystems, an air bearing motion system helps facilitation frictionlessconveyance in the Y-axis direction for a substrate placed on substratesupport apparatus 2250. Y-axis motion system 2355 can also optionallyuse dual rail motion, once again, provided by a linear air bearingmotion system or a linear mechanical bearing motion system.

Regarding motion systems supporting various carriage assemblies,printing system 2004 of FIG. 41 can have first X-axis carriage assembly2300A that is depicted having printhead assembly 2500 mounted thereuponand second X-axis carriage assembly 2300B that is depicted having cameraassembly 2550 mounted thereupon. Substrate 2050, which is on substratesupport apparatus 2250, can be located in various positions proximal tobridge 2130, for example, during a printing process. Substrate supportapparatus 2250 can be mounted on printing system base 2101. In FIG. 41 ,printing system 2004 can have first X-axis carriage assembly 2300A andsecond X-axis carriage assembly 2300B mounted on bridge 2130. FirstX-axis carriage assembly 2300A can also include first Z-axis movingplate 2310A for the Z-axis positioning of printhead assembly 2500, whilesecond X-axis carriage assembly 2300B can have second Z-axis movingplate 2310B for the Z-axis positioning of camera assembly 2550. In thatregard, various embodiments of carriage assemblies 2300A and 2300B canprovide precision X,Z positioning with respect to a substrate positionedon substrate support 2250 for printhead assembly 2500 and cameraassembly 2550, respectively. For various embodiments of printing system2004, first X-axis carriage assembly 2300A and second X-axis carriageassembly 2300B can utilize a linear air bearing motion system, which isintrinsically low-particle generating.

Camera assembly 2550 of FIG. 41 can be a high-speed, high-resolutioncamera. A camera assembly 2550 can include camera 2552, camera mountassembly 2554 and lens assembly 2556. Camera assembly 2550 can bemounted to motion system 2300B on Z-axis moving plate 2310B, via cameramount assembly 2556. Camera 2552 can be any image sensor device thatconverts an optical image into an electronic signal, such as by way ofnon-limiting example, a charge-coupled device (CCD), a complementarymetal-oxide-emiconductor (CMOS) device or N-typemetal-oxide-semiconductor (NMOS) device. Various image sensor devicescan be configured as an array of sensors for an area scan camera, or asingle row of sensors, for a line scan camera. Camera assembly 2550 canbe connected to image processing system that can include, for example, acomputer for storing, processing, and providing results. As previouslydiscussed herein for printing system 2004 of FIG. 41 , Z-axis movingplate 2310B can controllably adjust the Z-axis position of cameraassembly 2550 relative to substrate 2050. During various processes, suchas for example, printing and data collection, substrate 2050 can becontrollably positioned relative to the camera assembly 2550 using theX-axis motion system 2300B and Y-axis motion system 2355.

Accordingly, the split axis motion system of FIG. 41 can provide precisepositioning of the camera assembly 2550 and substrate 2050 relative toone another in three dimensions in order to capture image data on anypart of the substrate 2050 at any desired focus and/or height. Moreover,precision XYZ motion of a camera relative to a substrate can be done foreither area scanning or line scanning processes. As previously discussedherein, other motion systems, such as a gantry motion system, can alsobe used to provide precision movement in three dimensions between, forexample, a printhead assembly and/or a camera assembly, relative to asubstrate. Additionally, lighting can be mounted in various positions;either on an X-axis motion system or on a substrate support apparatusproximal to a substrate, and combinations thereof. In that regard,lighting can be positioned according to performing various lightfieldand darkfield analyses, and combinations thereof. Various embodiments ofa motion system can position camera assembly 2550 relative to substrate2050 using a continuous or a stepped motion or a combination thereof tocapture a series of one or more images of the surface of substrate 2050.Each image can encompass an area associated with one or more pixelwells, associated electronic circuitry components, pathways andconnectors of an OLED substrate. By using image processing, images ofparticles can be obtained, and size and number of particles of aspecific size determined. In various embodiments of systems and methodsof the present teachings, a line scan camera having about 8192 pixels,with a working height of about 190 mm, and capable of scanning at about34 kHz can be used. Additionally, more than one camera can be mounted onan X-axis carriage assembly for various embodiments of a printing systemsubstrate camera assembly, where each camera can have differentspecifications regarding field of view and resolution. For example, onecamera can be a line scan camera for in situ particle inspection, whilea second camera can be for regular navigation of a substrate in a gasenclosure system. Such a camera useful for regular navigation can be anarea scan camera having a field of view in the range of about 5.4 mm×4mm with a magnification of about 0.9× to about 10.6 mm×8 mm with amagnification of about 0.45×. In still other embodiments, one camera canbe a line scan camera for in situ particle inspection, while a secondcamera can be for precise navigation of a substrate in a gas enclosuresystem, for example, for substrate alignment. Such a camera useful forprecise navigation can be an area scan camera having a field of view ofabout 0.7 mm×0.5 mm with a magnification of about 7.2×.

With respect to in situ inspection of an OLED substrate, variousembodiments of a printing system substrate camera assembly, such ascamera assembly 2550 of printing system 2004 depicted in FIG. 41 , canbe used to inspect a panel without significant impact to total averagecycle time (TACT). For example, a Gen 8.5 substrate can be scanned foron-substrate particulate matter in less than 70 seconds. In addition toin situ inspection of OLED substrate, a printing system substrate cameraassembly can be used for a system validation study by using a testsubstrate to determine whether or not a sufficiently low particleenvironment for a gas enclosure system can be verified prior to usingthe gas enclosure system for a printing process.

With respect to airborne particulate matter and particle depositionwithin a system, a substantial number of variables can impact developinga general model that may adequately compute, for example, anapproximation of a value for particle fallout rate on a surface, such asa substrate, for any particular manufacturing system. Variables such asthe size of particles, the distribution of particles of particular size;surface area of a substrate and the time of exposure of a substratewithin a system can vary depending on various manufacturing systems. Forexample, the size of particles and the distribution of particles ofparticular size can be substantially impacted by the source and locationof particle-generating components in various manufacturing systems.Calculations based on various embodiments of gas enclosure systems ofthe present teachings suggest that without various particle controlsystems of the present teachings, on-substrate deposition per printcycle per square meter of substrate can be between more than about 1million to more than about 10 million particles for particles in a sizerange of 0.1 μm and greater. Such calculations suggest that that withoutvarious particle control systems of the present teachings, on-substratedeposition per print cycle per square meter of substrate can be betweenmore than about 1000 to about more than about 10,000 particles forparticles in a size range of about 2 μm and greater.

Using testing protocols as described for various embodiments anon-substrate particle determination testing protocol of the presentteachings, various embodiments of a low-particle gas enclosure system ofthe present teachings can maintain a low-particle environment providingfor an average on-substrate particle distribution that meets anon-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 10 μm in size. Various embodiments ofa low-particle gas enclosure system of the present teachings canmaintain a low-particle environment providing for an averageon-substrate particle distribution that meets an on-substrate depositionrate specification of less than or equal to about 100 particles persquare meter of substrate per minute for particles greater than or equalto 5 μm in size. In various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 2 μm in size. In various embodimentsof a gas enclosure system of the present teachings, a low-particleenvironment can be maintained providing for an average on-substrateparticle distribution that meets an on-substrate deposition ratespecification of less than or equal to about 100 particles per squaremeter of substrate per minute for particles greater than or equal to 1μm in size. Various embodiments of a low-particle gas enclosure systemof the present teachings can maintain a low-particle environmentproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.5 μm in size. For variousembodiments of a gas enclosure system of the present teachings, alow-particle environment can be maintained providing for an averageon-substrate particle distribution that meets an on-substrate depositionrate specification of less than or equal to about 1000 particles persquare meter of substrate per minute for particles greater than or equalto 0.3 μm in size. Various embodiments of a low-particle gas enclosuresystem of the present teachings can maintain a low-particle environmentproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.1 μm in size.

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

While embodiments of the present disclosure have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the disclosure.

It should be understood that various alternatives to the embodiments ofthe disclosure described herein may be employed in practicing thedisclosure. For example, while vastly different arts such as chemistry,biotechnology, high technology and pharmaceutical arts may benefit fromthe present teachings. OLED printing is used to exemplify the utility ofvarious embodiments of a gas enclosure system according to the presentteachings. Various embodiments of a gas enclosure system that may housean OLED printing system can provide features such as, but not limitedby, sealing providing an hermetic-sealed enclosure through cycles ofconstruction and deconstruction, minimization of enclosure volume, andready access from the exterior to the interior during processing, aswell as during maintenance. Such features of various embodiments of agas enclosure system may have an impact on functionality, such as, butnot limited by, structural integrity providing ease of maintaining lowlevels of reactive species during processing, as well as rapidenclosure-volume turnover minimizing downtime during maintenance cycles.As such, various features and specifications providing utility for OLEDpanel printing may also provide benefit to a variety of technologyareas. It is intended that the following claims define the scope of thedisclosure and that methods and structures within the scope of theseclaims and their equivalents be covered thereby.

What is claimed is:
 1. A method of processing of a substrate, the methodcomprising: depositing organic material from a printhead of an inkjetprinter onto a substrate positioned in a gas enclosure that houses aprinting system comprising the printhead; while depositing the organicmaterial: flowing a gas within the gas enclosure past the printhead andthrough a first housing located in the gas enclosure, the first housingcontaining the printhead; flowing the gas through a second housinglocated in the gas enclosure, the second housing containing a servicebundle operably coupled to the printing system; and filteringparticulate matter from the gas after the gas flows through the secondhousing.
 2. The method of claim 1, wherein filtering the particulatematter comprises flowing the gas to a dead space.
 3. The method of claim1, further comprising flowing the gas through a gas purification loopexternal to the gas enclosure.
 4. The method of claim 1, furthercomprising flowing the gas from a location proximate to a substratesupport disposed in the gas enclosure to the first housing.
 5. Themethod of claim 3, further comprising returning the gas from the gaspurification loop to the gas enclosure.
 6. The method of claim 5,wherein the organic material is an OLED material ink.
 7. The method ofclaim 5, wherein the organic material is a curable material used to forman encapsulation structure.
 8. The method of claim 5, further comprisingcuring the organic material deposited on the substrate.
 9. The method ofclaim 1, further comprising floating the substrate while depositing theorganic material on the substrate.
 10. The method of claim 1, whereinthe organic material is an OLED material ink.
 11. The method of claim 1,wherein the organic material is a curable material used to form anencapsulation structure.
 12. A method, comprising: depositing a materialon a substrate in a gas enclosure of an inkjet printer; while depositingthe material, flowing a gas within the gas enclosure and through a firsthousing located within the gas enclosure and enclosing a printheadassembly of the inkjet printer; while depositing the material, flowingthe gas from the first housing to a second housing located within thegas enclosure and enclosing a service bundle operably coupled to theinkjet printer; while depositing the material, flowing the gas from thesecond housing to a conduit fluidly connected to a gas circulation andfiltration system.
 13. The method of claim 12, further comprising, whiledepositing the material, flowing the gas through a gas purification loopexternal to the gas enclosure.
 14. The method of claim 12, whereindepositing the material comprises depositing ink on the substrate usingthe printhead assembly while floating the substrate on a floatationtable.
 15. The method of claim 12, wherein depositing the materialcomprises moving the printhead assembly with respect to the substrateand printing material from the printhead assembly onto the substrate.16. The method of claim 14, wherein the ink is an OLED material ink. 17.The method of claim 14, wherein the ink is a curable encapsulationmaterial.
 18. The method of claim 14, further comprising curing the inkdeposited on the substrate.
 19. The method of claim 14, furthercomprising floating the substrate while depositing ink on the substrateusing the printhead assembly.
 20. The method of claim 15, whereindepositing the material further comprises floating the substrate on afloatation table.